diff --git a/.vscode/settings.json b/.vscode/settings.json
index e0f15db..317e419 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,3 +1,10 @@
 {
-    "java.configuration.updateBuildConfiguration": "automatic"
+    "java.configuration.updateBuildConfiguration": "automatic",
+    "java.completion.filteredTypes": [
+        "com.sun.*",
+        "sun.*",
+        "jdk.*",
+        "org.graalvm.*",
+        "io.micrometer.shaded.*"
+    ]
 }
\ No newline at end of file
diff --git a/src/main/java/istlab/KisoJikken/JTAConsole.java b/src/main/java/istlab/KisoJikken/JTAConsole.java
index 0f44aa7..b065945 100644
--- a/src/main/java/istlab/KisoJikken/JTAConsole.java
+++ b/src/main/java/istlab/KisoJikken/JTAConsole.java
@@ -2,6 +2,8 @@
 
 import java.awt.Dimension;
 import java.awt.Point;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
 import java.awt.event.KeyEvent;
 import java.awt.event.KeyListener;
 import java.awt.event.MouseEvent;
@@ -14,6 +16,8 @@
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.UnsupportedEncodingException;
+import java.util.Arrays;
+import java.util.List;
 import java.util.Stack;
 
 import javax.swing.JFrame;
@@ -21,7 +25,11 @@
 import javax.swing.JTextArea;
 import javax.swing.text.BadLocationException;
 
-public class JTAConsole extends JTextArea implements Runnable, WindowListener, KeyListener, MouseListener {
+import com.github.difflib.text.DiffRow;
+import com.github.difflib.text.DiffRowGenerator;
+
+public class JTAConsole extends JTextArea
+        implements Runnable, WindowListener, KeyListener, MouseListener, ActionListener {
     // static JTAConsole lastWindow;
     // static Point lastActivePoint;
     static Stack<JTAConsole> winStack = new Stack<JTAConsole>();
@@ -32,6 +40,8 @@
     InputStreamReader isreader;
     BufferedReader reader;
     OutputStream outstream;
+
+    StringBuilder originalContent;
     // ProcessBuilder pb;
 
     // public JTAConsole(ProcessBuilder prob) {
@@ -69,10 +79,12 @@
         // }
         // lastWindow = this;
         winStack.push(this);
+        originalContent = new StringBuilder();
     }
 
     public void Systemoutprintln(String s) {
         append(s + "\n");
+        originalContent.append(s + "\n");
         int len = getDocument().getLength();
         setCaretPosition(len);
     }
@@ -101,9 +113,9 @@
 
         } catch (IOException | InterruptedException e) {
             // e.printStackTrace();
-            System.out.print(e.getClass().getCanonicalName()+" : ");
+            System.out.print(e.getClass().getCanonicalName() + " : ");
             System.out.println(e.getLocalizedMessage());
-        } 
+        }
 
         Systemoutprintln("=== end ===");
 
@@ -125,18 +137,18 @@
         Systemoutprintln("=== end ===");
     }
 
-    public static void main(String[] arg) {
-        ProcessBuilder processBuilder = new ProcessBuilder("ping", "localhost");
-        Process process = null;
-        try {
-            process = processBuilder.start();
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-        JTAConsole con = new JTAConsole("Demo");
-        con.startBR(process);
+    // public static void main(String[] arg) {
+    // ProcessBuilder processBuilder = new ProcessBuilder("ping", "localhost");
+    // Process process = null;
+    // try {
+    // process = processBuilder.start();
+    // } catch (IOException e) {
+    // e.printStackTrace();
+    // }
+    // JTAConsole con = new JTAConsole("Demo");
+    // con.startBR(process);
 
-    }
+    // }
 
     @Override
     public void windowOpened(WindowEvent e) {
@@ -184,7 +196,6 @@
     @Override
     public void windowActivated(WindowEvent e) {
         // JTAConsole.lastActivePoint = frame.getLocationOnScreen();
-
     }
 
     @Override
@@ -241,9 +252,10 @@
             byte[] sbyte = lastLineText.getBytes();
             outstream.write(sbyte);
             outstream.flush();
+            // originalContent.append("")
 
         } catch (BadLocationException | IOException e) {
-            e.printStackTrace();
+            System.out.println(e.getLocalizedMessage());
         }
     }
 
@@ -283,4 +295,34 @@
         // TODO Auto-generated method stub
 
     }
+
+    /**
+     * PopupMenuの選択によるコマンド実行
+     * 
+     * @param e
+     */
+    @Override
+    public void actionPerformed(ActionEvent e) {
+        if (e.getActionCommand().equals("Show Diff")) {
+            String orig = originalContent.toString(); // 出力情報のみ
+            String buffer = getText(); // JTAの内容（入力と、コメント含む） ここでの入力とは、擬似ターミナル経由でプロセスに送信した内容を指す
+            List<String> origList = Arrays.asList(orig.split("\n"));
+            List<String> bufList = Arrays.asList(buffer.split("\n"));
+            DiffRowGenerator generator = DiffRowGenerator.create()
+                    .showInlineDiffs(true)
+                    .inlineDiffByWord(true)
+                    .oldTag(f -> "~") // introduce markdown style for strikethrough
+                    .newTag(f -> "**") // introduce markdown style for bold
+                    .build();
+            List<DiffRow> rows = generator.generateDiffRows(origList, bufList);
+
+            System.out.println("|original|new|");
+            System.out.println("|--------|---|");
+            for (DiffRow row : rows) {
+                System.out.println("|" + row.getOldLine() + "|" + row.getNewLine() + "|");
+            }
+
+        } else if (e.getActionCommand().equals("Submit")) {
+        }
+    }
 }
diff --git a/src/main/java/istlab/KisoJikken/JTAConsolePopup.java b/src/main/java/istlab/KisoJikken/JTAConsolePopup.java
index b679f39..157e655 100644
--- a/src/main/java/istlab/KisoJikken/JTAConsolePopup.java
+++ b/src/main/java/istlab/KisoJikken/JTAConsolePopup.java
@@ -19,9 +19,13 @@
         add(mi);
         addSeparator();
 
+        mi = new JMenuItem("Show Diff");
+        add(mi);
+        mi.addActionListener(console); // コンソールに処理してもらう
+
         mi = new JMenuItem("Submit");
         add(mi);
-        mi.addActionListener(ae -> System.out.println(ae.getActionCommand()));
+        mi.addActionListener(console);
 
     }