ELECTRICITY STORAGE DEVICE

A technology of suppressing adhesion of an electrolyte solution to a portion near a liquid injection hole is provided. An electricity storage device includes an electrode body, an electrolyte solution, and a case. The case includes a body that includes an opening, and a sealing plate. The sealing plate includes a liquid injection hole through which the electrolyte solution is injected at a side closer to a first short side portion than a straight line passing through a middle point of a first long side portion and a middle point of a second long side portion. The sealing plate includes a pair of protrusions that protrude from an inner surface inwardly of the case. The pair of protrusions are provided in portions of the inner surface symmetrical with respect to the liquid injection hole in a long side direction of the sealing plate.