PURPOSE: To allow a caller to recognize the absence time of a called party by providing a timer operated for a time set by plural time set buttons setting different time, using the timer so as to control a voice synthesis circuit, and outputting a reply of absence residual time.

CONSTITUTION: When a user leaves it seat and its absence time is, e.g. 10 minutes or so, a 10min set button 65 is depressed and a timer 5 is activated for 10min. When a call signal is received in this state, the call signal is detected, a voice synthesis circuit 14 is operated to apply voice synthesis. Similarly, when its absence time is, e.g. 60 minutes or so, a 60min set button 6 is depressed and the timer 5 is operated for 60min. When the time elapses in this way and the residual time varies as 40min and then 30min, the voice synthesis circuit 14 is controlled on the time change information from the timer 5 and the voice synthesis according to the residual time is attained. Then the absence time is informed to the caller.