PURPOSE: To obtain a resin-sealed semiconductor device whose moistureproofness is excellent by a method wherein a wire which connects a semiconductor chip to a lead is covered with a resin provided with protruding and recessed parts.

CONSTITUTION: A semiconductor device is composed of the following: a tab 1; leads 3; a chip 2 mounted on the tab 1; wires 5 which connect the chip 2 to the leads 3; and a sealing body 4 with which the tab 1, the chip 2, the wires 5 and one part of the leads 3 are covered. In the semiconductor device, the wires 5 are covered with a resin 6 provided with protruding and recessed parts. For example, wires 5 are composed of Au, Cu or the like, and the wires whose diameter is 25 to 35μm are used. Their surface is covered with a polyimide resin-based insulating film 6 which has been formed to be protruding and recessed shapes ; the insulating film is formed to be about 5μm from the surface of the film up to high parts in the protruding parts of the film.