There is provided a mounting structure of electronic components wherein the heat sink is disposed so as to allow a high heat releasing property to be achieved and ensure that manufacturing is easy. The resin film is provided at the lower surface side of the whole circuit element to which the lead is connected; a molding resin is molded at the upper side from the lower surface of the lead including the side portions of the lead, the circuit element and the connecting portions of the lead and the circuit element; the lead is connected to the electrode of the circuit board so that flattened back surfaces of a plurality of one side resin-molded elements are on the same horizontal plane; and a single heat sink is mounted on the back surfaces of the plurality of one side resin-molded elements.