An object of the present invention is to provide a radio communication apparatus, a wireless LAN router, an unauthorized access prevention method, and a radio communication system that have security for protection against unauthorized access. A radio communication apparatus (1) according to the present invention includes: first radio communication means (10) for functioning as an access point for radio communication; second radio communication means (20) for functioning as an access point for radio communication; and storage means (21) for storing dummy information. The first radio communication means (10) has a security level higher than that of the second radio communication means (20), and the second radio communication means (20) is capable of transmitting the dummy information stored in the storage means (21).