A package 10 includes a housing 1 in which an electronic component 5 is mounted in a recess 1a having an opening on an upper surface and a screwing section 31 that is fixed on a side face of the housing 1 and extends in a lateral direction. The screwing section 31 includes a thin section 34 which is located on a distal end and is provided with a through hole 36 through which a screw is inserted, a thick section 35 which is located between the thin section 34 and the side face of the housing 1 and has a thickness less than that of the side face of the housing 1 and thicker than that of the thin section 34, and a screw fastening hole 37 which extends in the vertical direction in the thick section 35. Even if the housing 1 has warpage when the package 10 is fixed on the external substrate, heat dissipation from the package to the external substrate can be improved.