An information terminal device (terminal) has a first radio communication unit capable of performing radio communication with low power consumption and a second radio communication unit performing data communication using a wireless LAN. In an ad-hoc mode in which data communication is performed between the terminals, as a rule, the second radio communication unit is set in a sleep mode. However, when actual data communication is necessary, an activation signal is transmitted to a terminal as a communication party by using the first radio communication unit to activate the second radio communication unit. After completion of data communication, a stop signal is transmitted to the terminal as the communication party by using the first radio communication unit to stop the second radio communication unit on the transmission side. In such a manner, transmission of a beacon signal from the second radio communication unit is suppressed, and proper power saving is realized.