An electricity storage device includes: a plurality of cells that are aligned in a predetermined direction; a pair of end plates that sandwich the plurality of cells in the predetermined direction; and a restraining member that extends in the predetermined direction, is fixed to the pair of end plates, and exerts a restraining force on the plurality of cells in the predetermined direction via the end plates. Each of the end plates includes a first plate and a second plate. The first plate has a plurality of ribs on a surface that faces the adjacent cell and is formed of insulating material. The second plate is fixed to the first plate on a side opposite to the surface that faces the adjacent cell and is formed of material stronger than the insulating material for the first plate.