diff --git a/ui/.gitignore b/ui/.gitignore
index 40b878d..04c01ba 100644
--- a/ui/.gitignore
+++ b/ui/.gitignore
@@ -1 +1,2 @@
-node_modules/
\ No newline at end of file
+node_modules/
+dist/
\ No newline at end of file
diff --git a/ui/.prettierignore b/ui/.prettierignore
new file mode 100644
index 0000000..b022b85
--- /dev/null
+++ b/ui/.prettierignore
@@ -0,0 +1,12 @@
+# Build artifacts
+dist/
+build/
+
+# Dependencies
+node_modules/
+
+# Coverage
+coverage/
+
+# Generated files
+*.log
diff --git a/ui/src/components/CurrentTaskFooter.tsx b/ui/src/components/CurrentTaskFooter.tsx
index b10b5c2..fddbab7 100644
--- a/ui/src/components/CurrentTaskFooter.tsx
+++ b/ui/src/components/CurrentTaskFooter.tsx
@@ -1,6 +1,6 @@
 import { useEffect, useState } from "react";
 import { Task, Category } from "@/types/task";
-import { Square } from "lucide-react";
+import { Square, Pause } from "lucide-react";
 import { Button } from "@/components/ui/button";
 import { formatTimeAsHHmm } from "@/lib/utils";
 
@@ -8,12 +8,14 @@ interface CurrentTaskFooterProps {
   currentTask: Task | null;
   categories: Category[];
   onTaskTimer: (taskId: string, action: "start" | "stop" | "complete") => void;
+  onPauseTask: (task: Task) => void;
 }
 
 export const CurrentTaskFooter = ({
   currentTask,
   categories,
   onTaskTimer,
+  onPauseTask,
 }: CurrentTaskFooterProps) => {
   const [currentTime, setCurrentTime] = useState(new Date());
   const [elapsedTime, setElapsedTime] = useState(0);
@@ -93,6 +95,20 @@ export const CurrentTaskFooter = ({
             <p className="text-xs text-gray-500">経過時間</p>
           </div>
 
+          <Button
+            size="sm"
+            variant="outline"
+            onClick={() => onPauseTask(currentTask)}
+            className="hover:bg-orange-50"
+            style={{
+              color: "#ea580c",
+              borderColor: "#ea580c",
+            }}
+          >
+            <Pause className="h-4 w-4 mr-1" />
+            中断
+          </Button>
+
           <Button
             size="sm"
             variant="outline"
diff --git a/ui/src/components/task/SortableTask.tsx b/ui/src/components/task/SortableTask.tsx
index 876b89a..24e4bfe 100644
--- a/ui/src/components/task/SortableTask.tsx
+++ b/ui/src/components/task/SortableTask.tsx
@@ -1,7 +1,7 @@
 import { useSortable } from "@dnd-kit/sortable";
 import { CSS } from "@dnd-kit/utilities";
 import { Button } from "@/components/ui/button";
-import { GripVertical, Trash2, CalendarCheck } from "lucide-react";
+import { GripVertical, Trash2, CalendarCheck, Pause } from "lucide-react";
 import React from "react";
 import { TaskTimerButton } from "./TaskTimerButton";
 import { TaskTitleField } from "./TaskTitleField";
@@ -106,6 +106,9 @@ const SortableTask = ({ task }: SortableTaskProps) => {
   // タスクが完了しているかどうか
   const isCompleted = !!task.end_time;
 
+  // タスクが実行中かどうか
+  const isRunning = !!task.start_time && !task.end_time;
+
   return (
     <div
       ref={setNodeRef}
@@ -154,6 +157,18 @@ const SortableTask = ({ task }: SortableTaskProps) => {
       </div>
 
       <div className="flex gap-2 items-center">
+        {/* 中断ボタン：実行中のタスクのみ表示 */}
+        {isRunning && (
+          <Button
+            size="icon"
+            variant="outline"
+            onClick={() => taskActions.handlePauseTask(task)}
+            className="h-8 w-8 text-orange-500 hover:text-orange-700 hover:bg-orange-50"
+            title="中断"
+          >
+            <Pause className="h-4 w-4" />
+          </Button>
+        )}
         {/* 今日に移動ボタン：完了していない＆今日以外のタスクに表示 */}
         {!isCompleted && !isToday && (
           <Button
diff --git a/ui/src/contexts/TaskContext.tsx b/ui/src/contexts/TaskContext.tsx
index a40c77e..c659467 100644
--- a/ui/src/contexts/TaskContext.tsx
+++ b/ui/src/contexts/TaskContext.tsx
@@ -32,6 +32,7 @@ export interface TaskActions {
   ) => void;
   handleRepeatTask: (task: Task) => void;
   handleMoveToToday: (taskId: string) => void;
+  handlePauseTask: (task: Task) => void;
 }
 
 // タスクコンテキストの型定義
diff --git a/ui/src/hooks/useTaskActions.test.ts b/ui/src/hooks/useTaskActions.test.ts
new file mode 100644
index 0000000..6b578b5
--- /dev/null
+++ b/ui/src/hooks/useTaskActions.test.ts
@@ -0,0 +1,145 @@
+import { describe, it, expect } from "vitest";
+import { taskReducer } from "@/reducers/taskReducer";
+import { Task } from "@/types/task";
+
+describe("Task Pause Functionality", () => {
+  const mockRunningTask: Task = {
+    id: "1",
+    user_id: "user1",
+    title: "タスク1",
+    description: "説明",
+    estimated_minute: 30,
+    task_order: 1,
+    start_time: "2024-01-01T10:00:00Z",
+    end_time: null,
+    category_id: "cat1",
+    created_at: "2024-01-01T00:00:00Z",
+    task_date: "2024-01-01",
+  };
+
+  const mockTask2: Task = {
+    id: "2",
+    user_id: "user1",
+    title: "タスク2",
+    description: "",
+    estimated_minute: 20,
+    task_order: 2,
+    start_time: null,
+    end_time: null,
+    category_id: null,
+    created_at: "2024-01-01T00:00:00Z",
+    task_date: "2024-01-01",
+  };
+
+  describe("pause task behavior (completing task and creating new one)", () => {
+    it("should complete a running task by setting end_time", () => {
+      const initialState = [mockRunningTask, mockTask2];
+
+      // タスクを完了させる（end_timeを設定）
+      const action = {
+        type: "UPDATE_TASK" as const,
+        payload: {
+          id: "1",
+          end_time: "2024-01-01T11:00:00Z",
+        },
+      };
+
+      const newState = taskReducer(initialState, action);
+
+      // タスクが完了していることを確認
+      const completedTask = newState.find((t) => t.id === "1");
+      expect(completedTask?.end_time).toBe("2024-01-01T11:00:00Z");
+    });
+
+    it("should add a new task with same attributes after pausing", () => {
+      const initialState = [mockTask2];
+
+      // 同じ属性で新しいタスクを追加
+      const newTask: Task = {
+        id: "3",
+        user_id: mockRunningTask.user_id,
+        title: mockRunningTask.title,
+        description: mockRunningTask.description,
+        estimated_minute: mockRunningTask.estimated_minute,
+        task_order: null,
+        start_time: null,
+        end_time: null,
+        category_id: mockRunningTask.category_id,
+        created_at: "2024-01-01T11:00:00Z",
+        task_date: mockRunningTask.task_date,
+      };
+
+      const action = {
+        type: "ADD_TASK" as const,
+        payload: newTask,
+      };
+
+      const newState = taskReducer(initialState, action);
+
+      // 新しいタスクが追加されたことを確認
+      expect(newState).toHaveLength(2);
+      const addedTask = newState.find((t) => t.id === "3");
+      expect(addedTask).toBeDefined();
+      expect(addedTask?.title).toBe(mockRunningTask.title);
+      expect(addedTask?.estimated_minute).toBe(
+        mockRunningTask.estimated_minute,
+      );
+      expect(addedTask?.category_id).toBe(mockRunningTask.category_id);
+      expect(addedTask?.start_time).toBeNull();
+      expect(addedTask?.end_time).toBeNull();
+    });
+
+    it("should complete original task and add new task in sequence (simulating pause)", () => {
+      const initialState = [mockRunningTask, mockTask2];
+
+      // ステップ1: 実行中のタスクを完了
+      const completeAction = {
+        type: "UPDATE_TASK" as const,
+        payload: {
+          id: "1",
+          end_time: "2024-01-01T11:00:00Z",
+        },
+      };
+
+      const stateAfterComplete = taskReducer(initialState, completeAction);
+      const completedTask = stateAfterComplete.find((t) => t.id === "1");
+      expect(completedTask?.end_time).toBe("2024-01-01T11:00:00Z");
+
+      // ステップ2: 同じ属性で新しいタスクを追加
+      const newTask: Task = {
+        id: "3",
+        user_id: mockRunningTask.user_id,
+        title: mockRunningTask.title,
+        description: mockRunningTask.description,
+        estimated_minute: mockRunningTask.estimated_minute,
+        task_order: null,
+        start_time: null,
+        end_time: null,
+        category_id: mockRunningTask.category_id,
+        created_at: "2024-01-01T11:00:00Z",
+        task_date: mockRunningTask.task_date,
+      };
+
+      const addAction = {
+        type: "ADD_TASK" as const,
+        payload: newTask,
+      };
+
+      const finalState = taskReducer(stateAfterComplete, addAction);
+
+      // 最終的な状態を確認
+      expect(finalState).toHaveLength(3);
+
+      // 元のタスクが完了している
+      const original = finalState.find((t) => t.id === "1");
+      expect(original?.end_time).toBe("2024-01-01T11:00:00Z");
+
+      // 新しいタスクが未開始状態で追加されている
+      const newTaskInState = finalState.find((t) => t.id === "3");
+      expect(newTaskInState).toBeDefined();
+      expect(newTaskInState?.title).toBe(mockRunningTask.title);
+      expect(newTaskInState?.start_time).toBeNull();
+      expect(newTaskInState?.end_time).toBeNull();
+    });
+  });
+});
diff --git a/ui/src/hooks/useTaskActions.ts b/ui/src/hooks/useTaskActions.ts
index 1660185..b0e3416 100644
--- a/ui/src/hooks/useTaskActions.ts
+++ b/ui/src/hooks/useTaskActions.ts
@@ -1,7 +1,7 @@
 import React from "react";
 import { createClient } from "@/lib/supabase/client";
 import { useToast } from "@/components/ui/use-toast";
-import { TaskAction } from "@/types/task";
+import { TaskAction, Task } from "@/types/task";
 import { getTodayDateString } from "@/lib/utils";
 
 const supabase = createClient();
@@ -85,9 +85,84 @@ export const useTaskActions = (dispatch: React.Dispatch<TaskAction>) => {
     }
   };
 
+  // タスクを中断
+  const handlePauseTask = async (task: Task) => {
+    // 1. 現在のタスクに終了時刻を設定して完了させる
+    const endTime = new Date().toISOString();
+    const { error: updateError } = await supabase
+      .from("tasks")
+      .update({ end_time: endTime })
+      .eq("id", task.id);
+
+    if (updateError) {
+      toast({
+        title: "Error",
+        description: "タスクの中断に失敗しました",
+        variant: "destructive",
+      });
+      console.error("Error pausing task:", updateError);
+      return;
+    }
+
+    // ローカル状態を更新
+    dispatch({
+      type: "UPDATE_TASK",
+      payload: { id: task.id, end_time: endTime },
+    });
+
+    // 2. 同じ属性で新しいタスクを作成
+    const newTask = {
+      title: task.title,
+      description: task.description,
+      user_id: task.user_id,
+      estimated_minute: task.estimated_minute,
+      category_id: task.category_id,
+      task_date: task.task_date,
+      task_order: null,
+    };
+
+    const { data, error: insertError } = await supabase
+      .from("tasks")
+      .insert(newTask)
+      .select();
+
+    if (insertError) {
+      toast({
+        title: "Error",
+        description: "新しいタスクの作成に失敗しました",
+        variant: "destructive",
+      });
+      console.error("Error creating new task:", insertError);
+      return;
+    }
+
+    if (!data || data.length === 0) {
+      toast({
+        title: "Error",
+        description: "新しいタスクの作成に失敗しました",
+        variant: "destructive",
+      });
+      console.error("Error creating new task: No data returned");
+      return;
+    }
+
+    // 新しく作成したタスクをリストに追加
+    const createdTask = data[0] as unknown as Task;
+    dispatch({
+      type: "ADD_TASK",
+      payload: createdTask,
+    });
+
+    toast({
+      title: "Success",
+      description: `タスク "${task.title}" を中断しました`,
+    });
+  };
+
   return {
     handleDelete,
     handleTaskTimer,
     handleMoveToToday,
+    handlePauseTask,
   };
 };
diff --git a/ui/src/pages/TaskList/TaskList.tsx b/ui/src/pages/TaskList/TaskList.tsx
index c15fe05..f340324 100644
--- a/ui/src/pages/TaskList/TaskList.tsx
+++ b/ui/src/pages/TaskList/TaskList.tsx
@@ -683,6 +683,7 @@ const TaskList = () => {
         currentTask={currentRunningTask || null}
         categories={categories}
         onTaskTimer={taskActions.handleTaskTimer}
+        onPauseTask={taskActions.handlePauseTask}
       />
     </TaskProvider>
   );