To obtain a reinforcing frame capable of securing sufficient reinforcing strength and adhesive strength while suppressing a manufacturing cost by omitting a rim-like frame. A reinforcing frame is adhered to a rear surface, which is a non-light receiving surface of a solar battery panel, and includes a cylindrical portion that has a cylindrical shape along a longitudinal direction of the reinforcing frame and on which an adhesive surface for adhering to the solar battery panel is formed, and protruding portions that protrude from end portions along a longitudinal direction of the adhesive surface and that are substantially parallel to the adhesive surface.