diff --git a/frontend/messages/en.json b/frontend/messages/en.json
index 9dd02a9..3c049fb 100644
--- a/frontend/messages/en.json
+++ b/frontend/messages/en.json
@@ -19,5 +19,32 @@
     "create": "Create",
     "update": "Update",
     "please_enter": "Please enter project name"
+  },
+  "Project": {
+    "home": "Home",
+    "test_cases": "Test Cases",
+    "test_run": "Test Runs"
+  },
+  "Folders": {
+    "folder": "Folder",
+    "new_folder": "New Folder",
+    "edit_folder": "Edit Folder",
+    "delete_folder": "Delete Folder",
+    "folder_name": "Folder Name",
+    "folder_detail": "Folder Detail",
+    "close": "Close",
+    "create": "Create",
+    "update": "Update",
+    "please_enter": "Please enter folder name"
+  },
+  "Cases": {
+    "test_cases": "Test Cases",
+    "id": "ID",
+    "name": "Name",
+    "priority": "Priority",
+    "actions": "Actions",
+    "delete_case": "Delete test case",
+    "delete": "Delete",
+    "new_test_case": "New Test Case"
   }
 }
diff --git a/frontend/messages/ja.json b/frontend/messages/ja.json
index 69a99c8..142d36a 100644
--- a/frontend/messages/ja.json
+++ b/frontend/messages/ja.json
@@ -19,5 +19,32 @@
     "create": "作成",
     "update": "更新",
     "please_enter": "プロジェクト名を入力してください"
+  },
+  "Project": {
+    "home": "ホーム",
+    "test_cases": "テストケース",
+    "test_runs": "テストラン"
+  },
+  "Folders": {
+    "folder": "フォルダー",
+    "new_folder": "新規フォルダー",
+    "edit_folder": "フォルダーの編集",
+    "delete_folder": "フォルダーの削除",
+    "folder_name": "フォルダー名",
+    "folder_detail": "フォルダー詳細",
+    "close": "閉じる",
+    "create": "作成",
+    "update": "更新",
+    "please_enter": "フォルダ名を入力してください"
+  },
+  "Cases": {
+    "test_cases": "テストケース",
+    "id": "ID",
+    "title": "タイトル",
+    "priority": "優先度",
+    "actions": "アクション",
+    "delete_case": "テストケースを削除",
+    "delete": "削除",
+    "new_test_case": "新規テストケース"
   }
 }
diff --git a/frontend/src/app/[locale]/projects/[projectId]/Sidebar.tsx b/frontend/src/app/[locale]/projects/[projectId]/Sidebar.tsx
index c2f3a0e..51c9164 100644
--- a/frontend/src/app/[locale]/projects/[projectId]/Sidebar.tsx
+++ b/frontend/src/app/[locale]/projects/[projectId]/Sidebar.tsx
@@ -4,12 +4,14 @@ import { Listbox, ListboxItem } from "@nextui-org/react";
 import { Home, Files, FlaskConical } from "lucide-react";
 import { usePathname, useRouter } from "@/src/navigation";
 import useGetCurrentIds from "@/utils/useGetCurrentIds";
+import { ProjectMessages } from "@/types/project";
 
 export type Props = {
+  messages: ProjectMessages;
   locale: string;
 };
 
-export default function Sidebar({ locale }: Props) {
+export default function Sidebar({ messages, locale }: Props) {
   const { projectId } = useGetCurrentIds();
   const router = useRouter();
   const pathname = usePathname();
@@ -45,17 +47,17 @@ export default function Sidebar({ locale }: Props) {
   const tabItems = [
     {
       key: "home",
-      text: "Home",
+      text: messages.home,
       startContent: <Home strokeWidth={1} size={28} />,
     },
     {
       key: "cases",
-      text: "Test Cases",
+      text: messages.testCases,
       startContent: <Files strokeWidth={1} size={28} />,
     },
     {
       key: "runs",
-      text: "Test Runs",
+      text: messages.testRuns,
       startContent: <FlaskConical strokeWidth={1} size={28} />,
     },
   ];
diff --git a/frontend/src/app/[locale]/projects/[projectId]/folders/FolderDialog.tsx b/frontend/src/app/[locale]/projects/[projectId]/folders/FolderDialog.tsx
index 2d97ec6..bbdafad 100644
--- a/frontend/src/app/[locale]/projects/[projectId]/folders/FolderDialog.tsx
+++ b/frontend/src/app/[locale]/projects/[projectId]/folders/FolderDialog.tsx
@@ -11,13 +11,14 @@ import {
   ModalBody,
   ModalFooter,
 } from "@nextui-org/react";
-import { FolderType } from "@/types/folder";
+import { FolderType, FoldersMessages } from "@/types/folder";
 
 type Props = {
   isOpen: boolean;
   editingFolder: FolderType;
   onCancel: () => void;
   onSubmit: (name: string, detail: string) => void;
+  messages: FoldersMessages;
 };
 
 export default function FolderDialog({
@@ -25,6 +26,7 @@ export default function FolderDialog({
   editingFolder,
   onCancel,
   onSubmit,
+  messages,
 }: Props) {
   const [folderName, setFolderName] = useState({
     text: editingFolder ? editingFolder.name : "",
@@ -80,7 +82,7 @@ export default function FolderDialog({
       setFolderName({
         text: "",
         isValid: false,
-        errorMessage: "Please enter folder name",
+        errorMessage: messages.pleaseEnter,
       });
 
       return;
@@ -98,11 +100,13 @@ export default function FolderDialog({
       }}
     >
       <ModalContent>
-        <ModalHeader className="flex flex-col gap-1">Folder</ModalHeader>
+        <ModalHeader className="flex flex-col gap-1">
+          {messages.folder}
+        </ModalHeader>
         <ModalBody>
           <Input
             type="text"
-            label="Folder Name"
+            label={messages.folderName}
             value={folderName.text}
             isInvalid={folderName.isValid}
             errorMessage={folderName.errorMessage}
@@ -114,7 +118,7 @@ export default function FolderDialog({
             }}
           />
           <Textarea
-            label="Folder Detail"
+            label={messages.folderDetail}
             value={folderDetail.text}
             isInvalid={folderDetail.isValid}
             errorMessage={folderDetail.errorMessage}
@@ -128,10 +132,10 @@ export default function FolderDialog({
         </ModalBody>
         <ModalFooter>
           <Button variant="light" onPress={onCancel}>
-            Close
+            {messages.close}
           </Button>
           <Button color="primary" onPress={validate}>
-            {editingFolder ? "Update" : "Create"}
+            {editingFolder ? messages.update : messages.create}
           </Button>
         </ModalFooter>
       </ModalContent>
diff --git a/frontend/src/app/[locale]/projects/[projectId]/folders/FolderEditMenu.tsx b/frontend/src/app/[locale]/projects/[projectId]/folders/FolderEditMenu.tsx
index 79d1aec..0f811c7 100644
--- a/frontend/src/app/[locale]/projects/[projectId]/folders/FolderEditMenu.tsx
+++ b/frontend/src/app/[locale]/projects/[projectId]/folders/FolderEditMenu.tsx
@@ -6,8 +6,21 @@ import {
   DropdownItem,
 } from "@nextui-org/react";
 import { MoreVertical } from "lucide-react";
+import { FolderType, FoldersMessages } from "@/types/folder";
 
-export default function FolderEditMenu({ folder, onEditClick, onDeleteClick }) {
+type Props = {
+  folder: FolderType;
+  onEditClick: (folder: FolderType) => void;
+  onDeleteClick: (folder: FolderType) => void;
+  messages: FoldersMessages;
+};
+
+export default function FolderEditMenu({
+  folder,
+  onEditClick,
+  onDeleteClick,
+  messages,
+}: Props) {
   return (
     <Dropdown>
       <DropdownTrigger>
@@ -17,7 +30,7 @@ export default function FolderEditMenu({ folder, onEditClick, onDeleteClick }) {
       </DropdownTrigger>
       <DropdownMenu aria-label="Static Actions">
         <DropdownItem key="edit" onClick={() => onEditClick(folder)}>
-          Edit folder
+          {messages.editFolder}
         </DropdownItem>
         <DropdownItem
           key="delete"
@@ -25,7 +38,7 @@ export default function FolderEditMenu({ folder, onEditClick, onDeleteClick }) {
           color="danger"
           onClick={() => onDeleteClick(folder.id)}
         >
-          Delete folder
+          {messages.deleteFolder}
         </DropdownItem>
       </DropdownMenu>
     </Dropdown>
diff --git a/frontend/src/app/[locale]/projects/[projectId]/folders/FoldersPane.tsx b/frontend/src/app/[locale]/projects/[projectId]/folders/FoldersPane.tsx
index 1adc519..c6b147d 100644
--- a/frontend/src/app/[locale]/projects/[projectId]/folders/FoldersPane.tsx
+++ b/frontend/src/app/[locale]/projects/[projectId]/folders/FoldersPane.tsx
@@ -1,6 +1,6 @@
 "use client";
 import React from "react";
-import { FolderType } from "@/types/folder";
+import { FolderType, FoldersMessages } from "@/types/folder";
 import { useEffect, useState } from "react";
 import { Button, Listbox, ListboxItem } from "@nextui-org/react";
 import { Folder, Plus } from "lucide-react";
@@ -18,10 +18,11 @@ import {
 
 type Props = {
   projectId: string;
+  messages: FoldersMessages;
   locale: string;
 };
 
-export default function FoldersPane({ projectId, locale }: Props) {
+export default function FoldersPane({ projectId, messages, locale }: Props) {
   const router = useRouter();
   const pathname = usePathname();
   const [folders, setFolders] = useState([]);
@@ -112,7 +113,7 @@ export default function FoldersPane({ projectId, locale }: Props) {
           className="m-2"
           onClick={openDialogForCreate}
         >
-          New Folder
+          {messages.newFolder}
         </Button>
         <Listbox aria-label="Listbox Variants" variant="light">
           {folders.map((folder, index) => (
@@ -135,6 +136,7 @@ export default function FoldersPane({ projectId, locale }: Props) {
                   folder={folder}
                   onEditClick={onEditClick}
                   onDeleteClick={onDeleteClick}
+                  messages={messages}
                 />
               }
             >
@@ -149,6 +151,7 @@ export default function FoldersPane({ projectId, locale }: Props) {
         editingFolder={editingFolder}
         onCancel={closeDialog}
         onSubmit={onSubmit}
+        messages={messages}
       />
     </>
   );
diff --git a/frontend/src/app/[locale]/projects/[projectId]/folders/[folderId]/cases/CasesPane.tsx b/frontend/src/app/[locale]/projects/[projectId]/folders/[folderId]/cases/CasesPane.tsx
index c68ba6d..91336a8 100644
--- a/frontend/src/app/[locale]/projects/[projectId]/folders/[folderId]/cases/CasesPane.tsx
+++ b/frontend/src/app/[locale]/projects/[projectId]/folders/[folderId]/cases/CasesPane.tsx
@@ -2,14 +2,21 @@
 import { useEffect, useState } from "react";
 import TestCaseTable from "./TestCaseTable";
 import { fetchCases, createCase, deleteCase, deleteCases } from "./caseControl";
+import { CasesMessages } from "@/types/case";
 
 type Props = {
   projectId: string;
   folderId: string;
+  messages: CasesMessages;
   locale: string;
 };
 
-export default function CasesPane({ projectId, folderId, locale }: Props) {
+export default function CasesPane({
+  projectId,
+  folderId,
+  messages,
+  locale,
+}: Props) {
   const [cases, setCases] = useState([]);
   useEffect(() => {
     async function fetchDataEffect() {
@@ -51,6 +58,7 @@ export default function CasesPane({ projectId, folderId, locale }: Props) {
         onCreateCase={() => handleCreateCase(folderId)}
         onDeleteCase={handleDeleteCase}
         onDeleteCases={handleDeleteCases}
+        messages={messages}
         locale={locale}
       />
     </>
diff --git a/frontend/src/app/[locale]/projects/[projectId]/folders/[folderId]/cases/TestCaseTable.tsx b/frontend/src/app/[locale]/projects/[projectId]/folders/[folderId]/cases/TestCaseTable.tsx
index 679e615..9bdce23 100644
--- a/frontend/src/app/[locale]/projects/[projectId]/folders/[folderId]/cases/TestCaseTable.tsx
+++ b/frontend/src/app/[locale]/projects/[projectId]/folders/[folderId]/cases/TestCaseTable.tsx
@@ -16,14 +16,7 @@ import {
 } from "@nextui-org/react";
 import { Link, NextUiLinkClasses } from "@/src/navigation";
 import { Plus, MoreVertical, Trash, Circle } from "lucide-react";
-
-const headerColumns = [
-  { name: "ID", uid: "id", sortable: true },
-  { name: "Title", uid: "title", sortable: true },
-  { name: "Priority", uid: "priority", sortable: true },
-  { name: "Actions", uid: "actions" },
-];
-
+import { CasesMessages } from "@/types/case";
 import { priorities } from "@/config/selection";
 
 type Case = {
@@ -48,6 +41,7 @@ type Props = {
   onCreateCase: () => void;
   onDeleteCase: (caseId: number) => void;
   onDeleteCases: (selectedCases: string[]) => void;
+  messages: CasesMessages;
   locale: string;
 };
 
@@ -57,8 +51,16 @@ export default function TestCaseTable({
   onCreateCase,
   onDeleteCase,
   onDeleteCases,
+  messages,
   locale,
 }: Props) {
+  const headerColumns = [
+    { name: messages.id, uid: "id", sortable: true },
+    { name: messages.title, uid: "title", sortable: true },
+    { name: messages.priority, uid: "priority", sortable: true },
+    { name: messages.actions, uid: "actions" },
+  ];
+
   const [selectedKeys, setSelectedKeys] = useState<Selection>(new Set([]));
   const [sortDescriptor, setSortDescriptor] = useState<SortDescriptor>({
     column: "id",
@@ -121,7 +123,7 @@ export default function TestCaseTable({
                 className="text-danger"
                 onClick={() => onDeleteCase(testCase.id)}
               >
-                Delete test case
+                {messages.deleteCase}
               </DropdownItem>
             </DropdownMenu>
           </Dropdown>
@@ -163,7 +165,7 @@ export default function TestCaseTable({
   return (
     <>
       <div className="border-b-1 dark:border-neutral-700 w-full p-3 flex items-center justify-between">
-        <h3 className="font-bold">Cases</h3>
+        <h3 className="font-bold">{messages.testCases}</h3>
         <div>
           {(selectedKeys.size > 0 || selectedKeys === "all") && (
             <Button
@@ -173,7 +175,7 @@ export default function TestCaseTable({
               className="me-2"
               onClick={onDeleteCasesClick}
             >
-              Delete
+              {messages.delete}
             </Button>
           )}
           <Button
@@ -182,7 +184,7 @@ export default function TestCaseTable({
             color="primary"
             onClick={onCreateCase}
           >
-            New Test Case
+            {messages.newTestCase}
           </Button>
         </div>
       </div>
diff --git a/frontend/src/app/[locale]/projects/[projectId]/folders/[folderId]/cases/page.tsx b/frontend/src/app/[locale]/projects/[projectId]/folders/[folderId]/cases/page.tsx
index 35d594e..c62ec2f 100644
--- a/frontend/src/app/[locale]/projects/[projectId]/folders/[folderId]/cases/page.tsx
+++ b/frontend/src/app/[locale]/projects/[projectId]/folders/[folderId]/cases/page.tsx
@@ -1,16 +1,40 @@
 import CasesPane from "./CasesPane";
+import { useTranslations } from "next-intl";
 
 export default function Page({
   params,
 }: {
   params: { projectId: string; folderId: string; locale: string };
 }) {
+  const t = useTranslations("Cases");
+  const messages = {
+    testCases: t("test_cases"),
+    // folder: t("folder"),
+    // newFolder: t("new_folder"),
+    
+    // deleteFolder: t("delete_folder"),
+    id: t("id"),
+    title: t("title"),
+    priority: t("priority"),
+    actions: t("actions"),
+    deleteCase: t("delete_case"),
+    delete: t("delete"),
+    newTestCase: t("new_test_case"),
+    // projectName: t("folder_name"),
+    // projectDetail: t("folder_detail"),
+    // close: t("close"),
+    // create: t("create"),
+    // update: t("update"),
+    // pleaseEnter: t("please_enter"),
+  };
+
   return (
     <>
       <CasesPane
         projectId={params.projectId}
         folderId={params.folderId}
         locale={params.locale}
+        messages={messages}
       />
     </>
   );
diff --git a/frontend/src/app/[locale]/projects/[projectId]/folders/layout.tsx b/frontend/src/app/[locale]/projects/[projectId]/folders/layout.tsx
index 8fa2098..890c2a7 100644
--- a/frontend/src/app/[locale]/projects/[projectId]/folders/layout.tsx
+++ b/frontend/src/app/[locale]/projects/[projectId]/folders/layout.tsx
@@ -1,4 +1,5 @@
 import FoldersPane from "./FoldersPane";
+import { useTranslations } from "next-intl";
 
 export default function FoldersLayout({
   children,
@@ -7,9 +8,27 @@ export default function FoldersLayout({
   children: React.ReactNode;
   params: { projectId: string; locale: string };
 }) {
+  const t = useTranslations("Folders");
+  const messages = {
+    folder: t("folder"),
+    newFolder: t("new_folder"),
+    editFolder: t("edit_folder"),
+    deleteFolder: t("delete_folder"),
+    folderName: t("folder_name"),
+    folderDetail: t("folder_detail"),
+    close: t("close"),
+    create: t("create"),
+    update: t("update"),
+    pleaseEnter: t("please_enter"),
+  };
+
   return (
     <div className="flex w-full">
-      <FoldersPane projectId={params.projectId} locale={params.locale} />
+      <FoldersPane
+        projectId={params.projectId}
+        messages={messages}
+        locale={params.locale}
+      />
       <div className="flex-grow w-full">{children}</div>
     </div>
   );
diff --git a/frontend/src/app/[locale]/projects/[projectId]/layout.tsx b/frontend/src/app/[locale]/projects/[projectId]/layout.tsx
index 681f3e1..c702221 100644
--- a/frontend/src/app/[locale]/projects/[projectId]/layout.tsx
+++ b/frontend/src/app/[locale]/projects/[projectId]/layout.tsx
@@ -1,4 +1,5 @@
 import Sidebar from "./Sidebar";
+import { useTranslations } from "next-intl";
 
 export default function SidebarLayout({
   children,
@@ -7,10 +8,17 @@ export default function SidebarLayout({
   children: React.ReactNode;
   params: { locale: string };
 }) {
+  const t = useTranslations("Project");
+  const messages = {
+    home: t("home"),
+    testCases: t("test_cases"),
+    testRuns: t("test_runs"),
+  };
+
   return (
     <>
       <div className="flex border-t-1 dark:border-neutral-700 min-h-[calc(100vh-64px)]">
-        <Sidebar locale={locale} />
+        <Sidebar messages={messages} locale={locale} />
         <div className="flex w-full">
           <div className="flex-grow">{children}</div>
         </div>
diff --git a/frontend/types/case.ts b/frontend/types/case.ts
index 4e1d51a..280c82a 100644
--- a/frontend/types/case.ts
+++ b/frontend/types/case.ts
@@ -49,4 +49,15 @@ type AttachmentType = {
   caseAttachments: CaseAttachmentType;
 };
 
-export { CaseType, StepType, AttachmentType };
+export type CasesMessages = {
+  testCases: string;
+  id: string;
+  title: string;
+  priority: string;
+  actions: string;
+  deleteCase: string;
+  delete: string;
+  newTestCase: string;
+};
+
+export { CaseType, StepType, AttachmentType, CasesMessages };
diff --git a/frontend/types/folder.ts b/frontend/types/folder.ts
index 253eb5e..4150dd6 100644
--- a/frontend/types/folder.ts
+++ b/frontend/types/folder.ts
@@ -6,4 +6,17 @@ export type FolderType = {
   parentFolderId: number | null;
   createdAt: string;
   updatedAt: string;
-};
\ No newline at end of file
+};
+
+export type FoldersMessages = {
+  folder: string;
+  newFolder: string;
+  editFolder: string;
+  deleteFolder: string;
+  folderName: string;
+  folderDetail: string;
+  close: string;
+  create: string;
+  update: string;
+  pleaseEnter: string;
+};
diff --git a/frontend/types/project.ts b/frontend/types/project.ts
index 5a7d387..b9dd8b4 100644
--- a/frontend/types/project.ts
+++ b/frontend/types/project.ts
@@ -24,3 +24,9 @@ export type ProjectsMessages = {
   update: string;
   pleaseEnter: string;
 };
+
+export type ProjectMessages = {
+  home: string;
+  testCases: string;
+  testRuns: string;
+};