A laminate-type power storage element is configured of an exterior body that is formed in a flat bag shape by welding a first laminated film and a second laminated film by thermocompression bonding, and an electrode body that is sealed inside the exterior body, the electrode body having a sheet-shaped positive electrode and a sheet-shaped negative electrode. The first laminated film and the second laminated film respectively includes a first resin layer that has a property of transmitting a laser beam, a metal foil that is layered to the first resin layer, and a second resin layer is layered to the metal foil and has a thermal weldability.