A laminated power storage element includes: an exterior body shaped into a flat bag shape by laminating a pair of laminated films to weld a peripheral edge region; an electrode body sealed within the exterior body; a positive and a negative electrode terminal portion allowed to project outside the exterior body from a predetermined margin of the exterior body; and a pair of tab films welded on surfaces where the pair of laminated films oppose one another in a region along the predetermined margin to mutually weld the pair of laminated films, and the tab film covers an end surface of the laminated film while deviating outward from the exterior body from the predetermined margin, and covers both front and back surfaces of each of a base end of the positive electrode terminal portion and a base end of the negative electrode terminal portion.