PURPOSE: To provide the pushbutton telephone set releasing a radio line automatically and releasing each device from the talking state even when the radio line is connected due to the termination call operation left undone or mis- operation.

CONSTITUTION: This pushbutton telephone set provided with a call control means 2 controlling the communication of a terminal equipment and with a cordless telephone set 7 being at least one of terminal equipments is provided with a state monitor means 8 monitoring the communication state of the cordless telephone set 7 and commanding the end of a call of the cordless telephone set 7 to the call control means 2 when a radio lien is used ineffectively. When the cordless telephone set 7 uses ineffectively a radio line, the state monitor means 8 sends a signal commanding the end of call of the cordless telephone set 7 to the call control means 2 and the call control means 2 receiving the command controls the cordless telephone set 7 to allow it to terminate its call and then the radio line is released.