A repeatedly bendable power storage device is provided. A highly reliable power storage device is provided. A long-life power storage device is provided. A repeatedly bendable electronic device is provided. A flexible electronic device is provided. The power storage device includes a positive electrode, a negative electrode, and an exterior body wrapping the positive electrode and the negative electrode. The exterior body includes a metal layer and a resin layer. The thickness of the metal layer in at least part of an outer edge of the exterior body is smaller than that in a region other than the outer edge. The exterior body has a plurality of slits in the outer edge.