PURPOSE: To know the remaining time for announcement concretely by generating different announcing signals according to the selectively stored remaining time for announcement.

CONSTITUTION: When the remaining time of a timer 10 comes the remaining time 5min, 10min, 15min or 20min set and stored in a storage part 16 for the remaining time for announcement, respectively different announcing signals S33 wherein clock pulses P3 consist of 5, 10, 15 or 20 pulses are outputted from an AND circuit 33 according to the respective remaining times. The remaining time for announcement is announced by 5, 10, 15 or 20 times of intermittent sounding of a buzzer 44. When the timer 10 times out at the 0 remaining time, the announcing signal P10 of 10sec pulse width is outputted from an output terminal 0b and the buzzer 4 sounds for 10 seconds only.