A power storage device includes: a power storage stack which includes a plurality of power storage cells; a heating member that heats the power storage stack; a cooling member that cools the power storage stack; a first pressing member that presses the heating member against the power storage stack; a second pressing member that presses the cooling member against the power storage stack; and a sheet member covering the bottom of the power storage stack so that an enclosed space is formed between the sheet member and the power storage stack in a cross section of the power storage stack, wherein the sheet member has a first surface and a second surface, the cooling member is disposed on the first surface, within the enclosed space, and the heating member is disposed on the second surface, on an outer side of the enclosed space.