Abstract: An object of this invention is to effectively prevent a progress of corrosion due to a local cell produced between a copper raw material (30) of a lead frame and a plating layer (29) on the surface, secure an anchor effect necessary for a chip loading surface without providing a palladium or palladium alloy film (29) with an excessive thickness and improve the reliability of a semiconductor device while achieving a reduction of production cost of a semiconductor device.Ground plating layers (27), (28) of multilayer structure of nickel are formed entirely on the surface of the raw material and then the palladium or palladium alloy plating layer (29) is formed on the surface thereof. A first ground plating layer (27) is formed so as to have an elaborate quality by supplying a DC current of a predetermined current value thereto as a plating current.