diff --git a/org.ntlab.traceCollector/src/org/ntlab/traceCollector/tracer/MyPrintStream.java b/org.ntlab.traceCollector/src/org/ntlab/traceCollector/tracer/MyPrintStream.java
index 3732c3d..10872bd 100644
--- a/org.ntlab.traceCollector/src/org/ntlab/traceCollector/tracer/MyPrintStream.java
+++ b/org.ntlab.traceCollector/src/org/ntlab/traceCollector/tracer/MyPrintStream.java
@@ -1,8 +1,7 @@
 package org.ntlab.traceCollector.tracer;
 
 import java.io.PrintStream;
-import java.util.ArrayList;
-import java.util.LinkedList;
+import java.util.concurrent.ConcurrentLinkedQueue;
 
 /**
  * �g���[�X�o�͗p���[�e�B���e�B
@@ -12,19 +11,16 @@
  */
 public class MyPrintStream extends Thread {
 	private static MyPrintStream theInstance;
-	private static LinkedList<String> output;
+	private static ConcurrentLinkedQueue<String> output;
 	private static String s = null;
 	private static PrintStream sysout = null;
-//	private static boolean bFlushed = false;
-//	private static int count = 0;
 	
 	private static MyPrintStream getInstance() {
 		if (theInstance == null) {
 			theInstance = new MyPrintStream();
-			output = new LinkedList<String>();
+			output = new ConcurrentLinkedQueue<String>();
 			sysout = System.out;
 			Runtime.getRuntime().addShutdownHook(theInstance);		// �V���b�g�_�E���p
-//			theInstance.start();
 		}
 		return theInstance;
 	}
@@ -46,31 +42,10 @@
 	}
 
 	public void run() {
-//		if (count == 0) {
-//			// �ʏ�̃g���[�X�o��
-//			count++;
-//			String s;
-//			Runtime.getRuntime().addShutdownHook(new MyPrintStream());		// �V���b�g�_�E���p�ɂ����ЂƂƒC���X�^���X���쐬����
-//			while(!bFlushed) {
-//				try {
-//					Thread.sleep(10);
-//					if (output.size() > 0) {
-//						synchronized (output) {
-//							s = output.remove(0);
-//						}
-//						System.out.println(s);
-//					}
-//				} catch (InterruptedException e) {
-//					e.printStackTrace();
-//				}
-//			}
-//		} else {
-			// �V���b�g�_�E�����Ƀo�b�t�@�Ɏc�����g���[�X���o�͂��؂�
-//			bFlushed = true;
-			for (String s: output) {
-				sysout.println(s);
-			}			
-//		}
+		// �V���b�g�_�E����A�g���[�X���o�͂���
+		for (String s: output) {
+			sysout.println(s);
+		}			
 	}
 	
 	private synchronized void _print(int n) {