diff --git a/src/fr/devinsy/statoolinfos/uptime/UptimeSurveyor.java b/src/fr/devinsy/statoolinfos/uptime/UptimeSurveyor.java
index f0179a3..2d5d03a 100644
--- a/src/fr/devinsy/statoolinfos/uptime/UptimeSurveyor.java
+++ b/src/fr/devinsy/statoolinfos/uptime/UptimeSurveyor.java
@@ -21,10 +21,15 @@ package fr.devinsy.statoolinfos.uptime;
 import java.io.IOException;
 import java.net.HttpURLConnection;
 import java.net.URL;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import fr.devinsy.statoolinfos.util.Chrono;
+
 /**
  * The Class UptimeChecker.
  */
@@ -134,14 +139,50 @@ public class UptimeSurveyor
             result.add(new Uptime(url));
         }
 
+        Chrono chrono = new Chrono().start();
+
         //
         System.out.println("Survey of " + result.size());
+        /* MonoThread version.
         for (Uptime uptime : result)
         {
             int code = survey(uptime.getURL());
             uptime.update(code);
-            System.out.println("Uptime: " + uptime.getStatus().toString() + " " + uptime.getURL().toString());
+            System.out.println("Uptime: " + uptime.getStatus().toString() + " " +
+                    uptime.getURL().toString());
         }
+        */
+
+        ExecutorService pool = Executors.newFixedThreadPool(20);
+        for (Uptime uptime : result)
+        {
+            pool.execute(new Runnable()
+            {
+                @Override
+                public void run()
+                {
+                    int code = survey(uptime.getURL());
+                    uptime.update(code);
+                    System.out.println(Thread.currentThread().getId() + " Uptime: " + uptime.getStatus().toString() + " " + uptime.getURL().toString());
+                }
+            });
+        }
+
+        pool.shutdown();
+        while (!pool.isTerminated())
+        {
+            try
+            {
+                System.out.println("Wait for URL survey.");
+                pool.awaitTermination(5, TimeUnit.SECONDS);
+            }
+            catch (InterruptedException exception)
+            {
+                exception.printStackTrace();
+            }
+        }
+
+        System.out.println("URL Survey time: " + chrono.toString());
 
         //
         return result;