PURPOSE: To allow the user to recognize the arrival of a call in no sound by selecting automatically the incoming call mode to be the vibration mode when a vibrating device is connected to a portable telephone set, activating the vibrating device with the portable telephone set at the arrival of the call so as to allow the entire portable telephone set to obtain mechanical vibration.

CONSTITUTION: When a vibrating device 21 connects to a portable telephone set 11, a control circuit 14 recognizes the connection to set the incoming call mode to be the vibration mode. At the arrival of a call, the control circuit 14 gives an incoming call instruction to a control circuit 22 and the control circuit 22 activates a vibration unit driving circuit 23 to drive a vibration unit 24. Thus, when a call comes to the portable telephone set, since the vibrator is mechanically vibrated, the user of the telephone set recognizes the arrival of a call even in any state.