POWER STORAGE DEVICE

A power storage device includes a lower case (22) having a bottom portion (23) provided with a protrusion (25) that protrudes downward, and a cooler (30) located below the bottom portion (23). The cooler (30) includes a cooling portion (32A) having an end portion (37) that faces the protrusion (25) in a first direction perpendicular to an up-down direction. The cooling portion (32A) has an upper plate (35) and a lower plate (36) stacked in the up-down direction, and the upper plate (35) and the lower plate (36) are joined at respective joint surfaces in the end portion (37). The lower plate (36) has an extended portion (39) that extends toward the protrusion (25) further than the upper plate (35) in the end portion (37).