PURPOSE: To easily execute a time alarm in case of a dangerous work, by alarming present time information by a sound at prescribed time intervals, and automatically release the alarm after a prescribed interval of time has passed.

CONSTITUTION: A circuit 1 is constituted of a microcomputer, and is provided with both a storage function of alarm set time, and a coincidence detecting function of present time and the alarm set time. When the clock is set to an automatic time alarm mode by operating a mode selecting switch of a key switch part 2, the circuit 1 sends present time information to a sound synthesizing circuit 3 at prescribed time intervals in accordance with a program of the microcomputer. The circuit 3 converts this time information to language information by a sound, and sends it to an amplifier 4. An output of the amplifier 4 is converted to a sound by a loudspeaker 5. When a prescribed interval of time has passed after the time announcement, the automatic time alarm mode is released automatically.