A die pad is set down at a height lower than a height at which inner leads are provided and a level difference for the set-down becomes larger than a depth of a lower-mold cavity formed in a lower mold. The die pad is placed so that a back surface of the die pad is brought into contact with a lower-mold cavity bottom surface. The lead frame is clamped between the lower mold and an upper mold which has an upper-mold cavity and a suspension-lead relief groove formed to communicate with an end of an opening of the upper-mold cavity to achieve resin encapsulation.