There is provided a power storage device including: a power storage assembly; and a plurality of joined portions, each of the plurality of electrode plates including an electrode plate main body and a tab, the plurality of electrode plates being disposed such that the tabs are arranged in the stacking direction, the plurality of joined portions including a first joined portion configured to join the plurality of tabs to form a first bundle portion, and a second joined portion configured to join the plurality of tabs arranged in the stacking direction to form a second bundle portion, a part of the tabs in the first bundle portion and a part of the tabs in the second bundle portion being joined to the first joined portion and the second joined portion.