To address a worker performing a continuous single work every lapse of a fixed time in the work, and awake the consciousness to prevent an accident.

A start button 1, a recording button 6a, a microphone 6b, a speaker 5, variable set buttons 2a of a variable timer 2, indicating lamps 2b of variable set times of 5 min, 10 min, 20 min and 30 min, a selecting button 4a for a voice ROM 3, and four indicating lamps 4b are provided on the front of a plastic small box, and the timer 2, a voice channel 4 by a switching memory 4c and the voice ROM 3, a flash memory 7 for flashing all the selected indicating lamps 2b of the variable timer 2 during generation of a voice, and a resistor 8 as control means are integrated into the box.