A method of manufacturing a resin-encapsulated semiconductor device capable of supporting finer pitches comprises forming a metal plating layer on an inner lead and an outer lead of a lead. A semiconductor chip is mounted on a die pad, and an electrode on a surface of the semiconductor chip is electrically connected to the inner lead via a thin metal wire. The semiconductor chip, the thin metal wire and the inner lead are encapsulated by an encapsulation resin so that the outer lead extends beyond the encapsulation resin and is exposed. Resin burrs formed during resin encapsulation are removed by a defocused laser, and any metal adhered on the lead is lifted off.