Abstract: A package for housing semiconductor elements including an insulating base which consists of electrical insulation material, and has a mounting portion that mounts semiconductor elements on the upper surface as well as a plurality of depressions on either of the upper surface and the lower surface thereof, a plurality of metallized wiring layers led away from the periphery of the mounting portion and extending to one end surface of the depressions, a plurality of connection pads for electrically connecting the metallized wiring layers formed on the end surface of the depressions of the insulating base and terminals which are soldered to the connection pads, wherein the terminals are accurately attached by solder to designated positions on the connection pads and securely and strongly joined to designated wire conductors of external electronic circuit boards to achieve reliable electrical connections of semiconductor integrated circuit elements housed inside the package to external electronic circuit boards.