A cordless telephone system includes a master unit permanently connected to a wire telephone line, and a plurality of subsidiary units connected to the master unit by radio. A calling subsidiary unit includes a transmitter for transmitting a signal for requesting speech communication with another called subsidiary unit to the master unit through a radio channel which is monitored by the master unit, and a transmitter for transmitting a signal for calling the called subsidiary unit to the called subsidiary unit through a speech communication channel through which direct speech communication with the called subsidiary unit can be performed. The master unit includes a transmitter for receiving the signal for requesting speech communication from the calling subsidiary unit and transmitting a signal for requesting direct speech communication between the subsidiary units to the called subsidiary unit through a radio channel which is monitored by the called subsidiary unit. The called subsidiary unit includes transmitter which is started upon reception of the signal for requesting direct speech communication from the master unit, and receives the signal for calling the called subsidiary unit from the calling subsidiary unit through the speech channel.