PURPOSE: To contrive a reduction in the size of a device and a decrease in the thickness of the device by a method wherein a semiconductor element is placed on a thin-wall part provided on the surface of part of a lead fame, the element is connected with the lead frame and the element is molded with a resin to make small the thickness of the whole device.

CONSTITUTION: A semiconductor element 1 is placed on a lead frame 5 having a prescribed form and after the element 1 is electrically connected with the frame 5, the element 1 is molded with a resin. At that time, a thin-wall part 5a is provided on the surface of part of the frame 5 and the element 1 is placed on the part 5a. By placing the element 1 on the partial thin-wall part 5a of the frame 5, the thickness of a device becomes thin as the whole device. The periphery of the element 1 is molded with a resin to make up a shortage of the strength of the part 5a of the frame 5. Thereby, a reduction in the size of the device and a decrease in the thickness of the device are contrived.