Abstract: A semiconductor element (10) is secured to an island (7), and a plurality of through-holes (8) are formed in the portion of the island (7), which surrounds the area to which the semiconductor element (10) is secured. Further, the electrode pads of the semiconductor element (10) and leads (4) are electrically connected by copper wires (11). In this structure, the cost of materials is reduced by using the copper wires (11) in comparison with gold wires. Further, a part of a resin package (2) is embedded in through-holes (8), so that the island (7) can be easily supported within the resin package (2).