POWER STORAGE DEVICE

A power storage device includes: a power storage module including a plurality of stacked power storage cells; and a case having an inner space to accommodate the power storage module. The case includes a main body provided with an opening on an electrode terminal side of the plurality of power storage cells, a cover provided over the opening, and a tapered portion that narrows a width of the inner space in a direction from the opening toward a lower side of the main body.