To provide an intercom system with which a video signal is transmitted to a cordless handset and the cordless handset transmits a control data signal.
A cordless handset of the intercom system is provide with an ultrasonic wave reception circuit 302 that receives an ultrasonic wave signal from an interphone master set, a separation circuit 303 that separates a video signal from the received ultrasonic wave signal, a monitor unit 306 that outputs the separated video signal on its screen, a multiplexer circuit 316 that multiplexes a voice signal from a handset microphone on other data signals, a radio wave transmission circuit 317 that transmits the multiplexed voice signal to the interphone master set, an electric lock unlocking button 312, that is operated by the user confirming a visitor displayed on the monitor unit 306 and transmits a unlock control data signal 314 to unlock an electric lock unit 208, and a motor controller 313 that transmits a panning/tilting control data signal 315 to drive a monitor unit 112 thereby applying panning/tilting control to a camera unit 103.