diff --git a/ISCamRecorder/Program.cs b/ISCamRecorder/Program.cs
index 59eb4ff..d3e3f8e 100644
--- a/ISCamRecorder/Program.cs
+++ b/ISCamRecorder/Program.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using System.Windows.Forms;
 
@@ -11,6 +12,16 @@
         /// </summary>
         [STAThread]
         static void Main() {
+            //ミューテックス作成
+            Mutex app_mutex = new Mutex(false, "ISCamRecorder_Mutex");
+
+            //ミューテックスの所有権を要求する
+            if (app_mutex.WaitOne(0, false) == false) {
+                MessageBox.Show("本ソフトウェアは複数起動できません。");
+                return;
+            }
+
+            // 起動
             Application.EnableVisualStyles();
             Application.SetCompatibleTextRenderingDefault(false);
             Application.Run(new MainForm());