In an encryption key setting system of the present invention, in response to an operation of a registration button 127, an access point 20 restricts the coverage of radio wave transmitted from the access point 20 from a general radio communication area AR1 to a narrower security communication area MR1. The access point 20 subsequently delivers a WEP key to a terminal 50, confirms the successful delivery, and registers a MAC address of the terminal 50. The terminal 50 sets the delivered WEP key in itself. This arrangement desirably allows for new enrollment of a terminal for a wireless LAN by a simple method, while effectively preventing leakage of data representing an encryption key.