A power storage device includes a battery containing body, an electronic device unit, and a chassis for housing them, wherein at a side surface portion of the chassis, an opening for inserting and removing the battery containing body and the electronic device unit is provided; an openable and closable pivoting member is provided inside the opening, the pivoting member, when closed, preventing removal of the battery containing body, and when opened, preventing insertion of the electronic device unit as removed; and the electronic device unit is housed and disposed adjacent to the battery containing body, and includes an opening prevention guide capable of engaging with the pivoting member and thereby preventing the pivoting member from being opened when the electronic device unit is housed.