A tab lead including a first insulating film made of resin is adhered to one of surfaces of a part of a region of a metal plate in a length direction of the metal plate and a second insulating film made of resin is adhered to the other surface of the part of the region. Both end portions of the first insulating film and both end portions of the second insulating film are integrally welded to each other. First protruding portions protruding outward in a thickness direction of the first insulating film are formed at regions of the first insulating film corresponding to both widthwise side edges of the metal plate and vicinities thereof. Second protruding portions protruding outward in a thickness direction of the second insulating film are formed at regions of the second insulating film corresponding to both widthwise side edges of the metal plate and vicinities thereof.