In a substrate, at least one lateral surface between one surface and another surface is a cut surface that is cut together with mold resin. The mold resin, which is cut together with the substrate, is provided with a surface that is flush with the cut surface. A portion of the mold resin constituting the surface flush with the cut surface has a surface that is joined to the surface flush with the cut surface and parallel to the one surface of the substrate; this portion is thinner than a portion that seals electronic parts. Consequently, the mold resin is cut with a dicing blade brought into contact with a surface parallel to the one surface of the substrate.