diff --git a/src/main/java/info/istlab/ServerTester/App.java b/src/main/java/info/istlab/ServerTester/App.java
index 9916a9e..458ab5d 100644
--- a/src/main/java/info/istlab/ServerTester/App.java
+++ b/src/main/java/info/istlab/ServerTester/App.java
@@ -4,6 +4,7 @@
     public static boolean isWindows;
     public static String userhome;
     public static String userdir;
+    public static boolean isJAR = false;
 
     static {
         String os = System.getProperty("os.name").toLowerCase();
@@ -13,6 +14,10 @@
     }
 
     public static void main(String[] args) {
+        Class<?> clazz = App.class; // Mainクラスを指定
+        String location = clazz.getProtectionDomain().getCodeSource().getLocation().getPath();
+        isJAR = location.endsWith(".jar");
+
         Host myhost = new Host();
 
         WebServer web = new WebServer(8081);
@@ -27,7 +32,7 @@
         ThreadTimeServer ttime = new ThreadTimeServer(11123);
         myhost.addPanel(new ServerPanel(ttime, myhost));
 
-        EchoServer echo = new EchoServer(10008,"127.0.0.1");
+        EchoServer echo = new EchoServer(10008, "127.0.0.1");
         myhost.addPanel(new ServerPanel(echo, myhost));
 
         ThreadEchoServer techo = new ThreadEchoServer(11008);
diff --git a/src/main/java/info/istlab/ServerTester/JExecutor.java b/src/main/java/info/istlab/ServerTester/JExecutor.java
index 2f1a6f4..fc7917a 100644
--- a/src/main/java/info/istlab/ServerTester/JExecutor.java
+++ b/src/main/java/info/istlab/ServerTester/JExecutor.java
@@ -52,6 +52,11 @@
 
         }
         comlist.add("java");
+        // JARで起動した場合は、クラスパスでJARファイルを指定する
+        if (App.isJAR) {
+            comlist.add("-cp");
+            comlist.add(App.userdir + "/ServerTester-1.0-launcher.jar");
+        }
         comlist.add(pkgname + "." + javafname);
         // コマンドラインオプションをtrimした結果が空文字列なら追加しない
         if (commandLineOption.trim().length() > 0) {
@@ -71,9 +76,15 @@
             con.Systemoutprintln(CommandRunner.prompt + "java " + pkgname + "." + javafname + " " + commandLineOption);
         }
         // ProcessBuilder processBuilder = new ProcessBuilder("pwd");
-        File dir = new File(App.userdir + "/target/classes");
-        System.out.println("[JExecutor] chdir to "+dir.getAbsolutePath());
-        processBuilder.directory(dir);
+        if (App.isJAR) {
+            File dir = new File(App.userdir);
+            System.out.println("[JExecutor:JAR] chdir to " + dir.getAbsolutePath());
+            processBuilder.directory(dir);
+        } else {
+            File dir = new File(App.userdir + "/target/classes");
+            System.out.println("[JExecutor] chdir to " + dir.getAbsolutePath());
+            processBuilder.directory(dir);
+        }
         // processBuilder.inheritIO();
         try {
             process = processBuilder.start();