Abstract: Disclosed are a lead frame for a semiconductor device, and a semiconductor device using the lead frame. Inner leads and outer leads of the lead frame are formed to have such a sectional structure that a film of Pd or a Pd alloy is formed on both surfaces or a rear surface of a lead frame directly or through an undercoat, and an Au-plated film is formed on a part of the film of Pd or a Pd alloy. Pd and Au are not applied to unnecessary areas, thus resulting in higher economical and production efficiency. The lead frame has good quality, is economical and has superior productivity. Wires connecting a semiconductor chip and the inner leads have a good connection property and joint portions of the outer leads to an external device also have a good connection property.