A semiconductor device manufacturing method which enhances the reliability of a semiconductor device. The method includes a step in which a source wire is connected with a semiconductor chip while jigs are pressed against a die pad. The jigs each have a first support portion with a first projection and a second support portion with a second projection. Using the jigs thus structured, the first projection is made to contact with a first point on the front surface of the die pad and then the second projection is made to contact with a second point on the front surface of the die pad located closer to a suspension lead than the first point.