diff --git a/YACOSCore/ejbModule/org/yacos/core/users/UserManagerBean.java b/YACOSCore/ejbModule/org/yacos/core/users/UserManagerBean.java
new file mode 100644
index 0000000..5401e0a
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/users/UserManagerBean.java
@@ -0,0 +1,66 @@
+/**
+ * 
+ */
+package org.yacos.core.users;
+
+import java.util.Collection;
+
+import javax.ejb.Stateless;
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+
+import org.yacos.core.exceptions.PKAlreadyUsedException;
+
+/**
+ * @author christiancorsano
+ *
+ */
+@Stateless
+public class UserManagerBean implements IUserManager{
+	@PersistenceContext
+	EntityManager em;
+	
+	@SuppressWarnings("unchecked")
+	public Collection<User> getUsers(){
+		Query query = em.createNativeQuery("from User", User.class);
+		return query.getResultList();
+	}
+	
+	/**
+	 * Adds a user into the system 
+	 * throw PKAlreadyUsedException if login exist in the DB 
+	 * @param user
+	 */
+	public void addUser(User user) throws PKAlreadyUsedException{
+		if (!this.existe(user)){
+			em.persist(user);
+		}
+		else{
+			throw new PKAlreadyUsedException();
+		}
+	}
+	
+	/**
+	 * Removes a user from the system
+	 * @param user
+	 */
+	public void removeUser(User user){
+		User persistedUser = em.find(User.class, user.getLogin());
+		em.remove(persistedUser);
+	}
+
+	public User getUser(String login) {
+		return em.find(User.class, login);
+	}
+	
+	public void UpdateUser(User user){
+		em.merge(user);
+	}
+	
+	public Boolean existe(User user){
+	  return (this.getUser(user.getLogin())!= null); 
+	}
+
+	
+}