To prevent the occurrence of disturbance in a mobile station without relying on the common sense of a user by permitting a base station to transmit an inactivation signal to the mobile station and permitting the mobile station to inactivate the use of its output in accordance with the inactivating signal.

A switch-on signal is supplied to a switch 4 with connections 10 and the switch 4 supplies a signal generation signal to a signal generator 5 in accordance with it. The signal generator 5 generates the inactivation signal and it is transmitted with a transmitter 8, a fork 7 and an antenna 2. A transmitter/receiver 21 receives the inactivation signal with the antenna 22, the fork 26 and a receiver 30. A detector detects the reception of the respective inactivation signals and permits the signal generator 27 to generate a signal generating signal provided with a fixed duration time in accordance with the detection every time. A transmitter 23 inactivates a transmission output in accordance with the signal generating signal during the period of length in the signal generating signal. As a result, the transmission output of the transmitter/receiver 21 and the transmission outputs of the whole mobile stations near the base station 1 cannot be used.