PURPOSE: To get the life of an alarm and the inspection time therefor to be informed and also simplify a circuit by attaching a timer circuit to the device.

CONSTITUTION: An alarm 1 for gas leakage with a timer has a detector 4 composed of a gas leakage detector 2 and an alaming part 3 giving the alarm in accordance with a detection signal. In addition, the device is equipped with the timer circuit 15 formed by using an electric volume storing element 18 so as to inform the life of the alarm 1, and by changing the average current value of the output S3 of a pulse generator 16 which supplies the current to the element 18, the adjustment of the set time is performed by the element 18 and PUT 19, while in response to the detection action, the output S3 is gated 44, and thereby the alarming part 3 is driven.