POWER STORAGE DEVICE

A power storage device includes a plurality of power storage elements, a heat exchange plate disposed between the plurality of power storage cells so as to face respective long side surfaces of the plurality of power storage cells and extending in a long-side direction of the long side surface, a main supply pipe through which a coolant flows to the heat exchange plate, and a housing case that houses the plurality of power storage cells, the heat exchange plate, and the main supply pipe. The housing case is provided with a partition wall disposed between the main supply pipe connected to the heat exchange plate and the power storage cell when viewed in an up-down direction.