A case includes a main case body and an exterior member. The exterior member is welded to the main case body with laser light. The laser light is irradiated onto a welding part of the main case body and the exterior member and reflected at an irradiation surface, and a reflected-light receiving part is formed at a position where the reflected laser light is irradiated according to an incidence angle of the laser light to the irradiation surface. The exterior member includes a flange part which is disposed on an upper side of the main case body and which protrudes toward an inner side of the main case body. A lower surface of the flange part includes a module receiving surface which receives a module to be disposed inside the main case body, and the reflected-light receiving part is formed at a part of the module receiving surface.