BATTERY PACK

A battery pack includes a cell-stacked body in which a plurality of battery cells including gas release valves are stacked, a gas release duct which connects the gas release valves of the plurality of battery cells, and a battery case which accommodates the cell-stacked body and the gas release duct. The battery pack is capable of discharging a gas from the gas release duct to an outside of the battery case. A check valve configured to allow a flow of the gas from the gas release valves to the outside of the battery case and to restrict entry of a foreign matter from the outside of the battery case is provided in the battery case.