A service plug includes a body portion including a pair of power bus bars that are connected to a power supply circuit by being connected to a first terminal of a connector, a switching lever portion including an interlock terminal that brings the power supply circuit into a closed state when being in a state of conduction with a second terminal of the connector, and brings the power supply circuit into an open state when being in a state of non-conduction with the second terminal of the connector, and a power interruption portion that brings the interlock terminal 32 of the switching lever portion into a state of non-conduction with the second terminal to bring the power supply circuit into an open state by using an actuator that is operated in accordance with a collision detection signal for a vehicle.