Abstract: A semiconductor chip is bonded onto a die pad portion of a lead frame including nickel/palladium/gold stacked plate layers. Then, a first bonding procedure is carried out with a metal wire of gold pressed against an electrode pad of the semiconductor chip while applying a load of approximately 60 g and ultrasonic waves with a power of approximately 55 mW by using a bonding tool. Subsequently, a second bonding procedure is carried out with the metal wire pressed against an inner lead portion of the lead frame while applying a load of 150 through 250 g and the ultrasonic waves with a power of 0 through 20 mW. In the second bonding procedure, the wire bonding in conformity with the property of the stacked plate layers can be conducted using a large load and a small ultrasonic power, resulting in attaining firm bonding in a short period of time without causing peeling of the gold plate layer.