To realize a means by which the sticking of insulating tape on a lead frame, the separation of radiating plates one by one from a radiating plate sheet and the sticking of the radiating plate on the lead frame can be performed by sequential manufacturing operations.

A guide hole is formed in a lead frame 1, in an insulating film and in a radiating plate sheet 7, respectively. First, the lead frame 1 and the insulating film are positioned using the holes for positioning formed in them, respectively. Then the insulating film is cut out in a desired shape and the cut film is stuck on the lead frame 1. After that, the lead frame 1 on which the insulating film is stuck and the radiating plate sheet 7 are positioned using the positioning holes made in them, respectively. A radiating plate is punched from the radiating plate sheet 7 with a punching die 10. The punched radiating plate is pressed against the insulating film on the lead frame and is stuck on it.