PURPOSE: To obtain an alarm clock in which money can be saved smoothly by inserting a coin into the alarm clock to conduct a contact and stopping the sound by turning off a switch.

CONSTITUTION: When an alarm clock 1 is operated, the clock 1 is set to a sounding time. When a coin is inserted into a coin throw-in port 2 of the clock, the coin is held by a coin holder 3 and a switch 4 and a contact 5 is conducted by the coin. Consequently, a circuit passing through the contact 5, the coin, and the alarm part of the clock 1 is established through a conducting wire 6 thus providing the function of an alarm clock. When the sound of alarm clock is stopped, a switch 7 is depressed to open a switch 4 downward. Consequently, the coin in the coin holder 3 falls gravitationally and the contact 5 is opened to stop the sound. The coin is stored in a storing part 8 and the switch 4 is reset to the coin holding position by means of a spring.