The battery pack includes a base having a heat dissipation wall, a switching device for controlling current having a plurality of electrode terminals, being disposed so as to be capable of transferring released heat to the heat dissipation wall, and a bus bar having a connection terminal that is connected to the switching device or a unit cell so as to enable energization. The connection terminal is disposed so as to be positioned in an area corresponding to a width of the switching device in a direction in which the electrode terminals are arranged in line and in an area extending to a periphery of the switching device in a direction orthogonal to the direction in which the electrode terminals are arranged in line.