PURPOSE: To provide an earthquake-sensitive automatic power supply interrupting device which can be easily, stably, and surely attached to a switchboard installed to an ordinary house, etc., and is not easily reset after power supply is interrupted.

CONSTITUTION: A holding means holds an interrupting signal which is outputted from an earthquake-sensitive switch when the switch detects vibrations or an impact and turns off a pilot lamp 5. When the interrupting signal is inputted to a one-shot circuit from the holding means, the circuit drives a plunger 14a for a fixed period of time by making a driving current to flow to a solenoid 14. The driving force drives a push rod 18 through an arm 17 and the rod 18 sets the isolating switch of a circuit breaker to an opened state by pressing a test button for a fixed period of time. Because the holding means holds the interrupting signal until a reset switch 4 is pressed, the lamp 5 is not lighted and no electric power is supplied until the isolating switch of the circuit breaker is reset.