A power storage module has a plurality of power storage elements whose electrode terminals, which include a positive electrode and a negative electrode, are arranged on an electrode arrangement surface, and a connection module that is mounted to the electrode arrangement surface of the plurality of power storage elements. The connection module has an insulating protector holding a bus bar, which connects adjacent electrode terminals of the plurality of power storage elements. The insulating protector has a front wall and a rear wall that intersect a virtual plane that is parallel to the electrode arrangement surface. The front wall and the rear wall are respectively provided with protruding portions, and the protruding portions that are respectively provided on the front wall and the rear wall engage with a plurality of extending portions that are provided on the electrode arrangement surface of the plurality of power storage elements.