A circuit breaker device is provided with a main contactor part that can switch between connection and disconnection of a battery and a circuit, and a circuit breaker (10a) that can disconnect the battery. The circuit breaker (10a) is provided with: a connector connection part (41b) having a pair of connector circuit terminals (41bp, 41bn) related to passing electricity through a coil for the main contactor part; a connector (43) that is attachable to and detachable from the connector connection part (41b) and has a connector shorting terminal (43a) that shorts the pair of connector circuit terminals (41bp, 41bn) upon attachment to the connector connection part (41b); and a claw part (44a) for restricting attachment of the connector (43) to the connector connection part (41b).