To provide a sheet-like power storage device which can be curved or bent in at least one axis direction. A power storage device includes a power storage element including a plurality of flexible sheet-like positive electrodes each having one end portion fixed to a positive electrode tab; a plurality of flexible sheet-like negative electrodes each having one end portion fixed to a negative electrode tab; and a plurality of flexible sheet-like separators. The positive electrodes and the negative electrodes are alternately stacked so as to overlap with each other with the separator interposed therebetween. The power storage element is sealed in a flexible exterior body.