Electricity storage device including a plurality of cooling layers

An electricity storage device includes an electricity storage module and a cooling device disposed adjacent to the electricity storage module. The cooling device includes a first cooling layer that is adjacent to the electricity storage module and a second cooling layer that is located on the opposite side of the first cooling layer from the electricity storage module. In the first cooling layer, a plurality of first cooling channels that is disposed at intervals in an array direction and first walls that are located between the first cooling channels are formed. In the second cooling layer, a plurality of second cooling channels that is disposed at intervals in the array direction and second walls that are located between the second cooling channels are formed. At least some of the first walls are disposed so as to be offset from the second walls.