To detect whether a wireless LAN interface device belongs to a wireless LAN area when the interface device stops and a cellular wireless interface device conducts communication, and switch the communication via the cellular wireless interface device to communication via the wireless LAN interface device.

A mobile radio terminal 101 includes a cellular wireless area detection part 216 for detecting whether the terminal belongs to the cellular wireless area to generate cellular wireless area information and a wireless LAN area detector 204 for detecting whether the terminal belongs to the wireless LAN area to generate wireless LAN area information. It establishes a communication session with the cellular wireless system, and hands over from the communication via the cellular wireless system to the communication via the wireless LAN system when the cellular wireless area information and the wireless LAN area information indicate that the terminal belongs to the cellular wireless area and the wireless LAN area.