A communication system is constructed in such a manner that a user is allowed to designate a controller 1 and a wireless device 3 simultaneously to start authentication for connection with a wireless base station 2 to specify the device to be connected, and to establish connection authentication without a password for the first time. Thereafter, the controller 1 distributes a password to the wireless base station 2 and to the wireless device 3 to cancel the connection authentication. Next, connection authentication with the distributed password is established. Thus, the communication system makes it possible to substantially automatically establish connection authentication, thereby eliminating a cumbersome operation by the user in implementing the connection authentication process.