A power storage apparatus mounted with a plurality of connected power storage modules and capable of charging or discharging an electric power, and in which a housing is partitioned by a partition plate to be divided into a power storage area and a control device area; in the power storage area, an opening is formed, and the power storage modules are contained; in the control device area, an opening is formed, and a switching protective device section to switch and protect the power storage modules is contained; a main circuit wiring from the power storage modules is led out of the control device area via the switching protective device section; the opening of the power storage area is covered with a detachable cover; and the opening of the control device area is covered with a detachable cover independent of the cover of the opening of the power storage area.