Cell selection circuit includes a plurality of first wiring switches, and that selectively connect one of both ends of a selected cell to first wiring and at least one second wiring switch that selectively connects the other end of both the ends of the selected cell to second wiring. Clamp circuit includes clamp switches for forming a closed loop including inductor in a state where cell selection circuit does not select any cell. Controller turns on all of a plurality of switching elements forming a discharge path after the clamp state is ended, and then turns on a part of a plurality of switching elements constituting clamp switch before the state is switched to a next clamp state.