To prevent exposure of a semiconductor chip, bonding wires, etc., and generation of voids, by forming bent parts bent in a lead frame thickness direction on a supporting lead.

A semiconductor chip is mounted on a die pad 1 via a pellet fixing member such as adhesive agent, and electrodes of the semiconductor chip are bonded to inner leads 4 of a lead frame by using wires such as gold wires. After molding is performed with resin such as epoxy resin, outer leads 6 are formed. In this lead frame, bent parts 2a are formed in a frame thickness direction on both sides of a supporting lead 2, so that change of flowing balance of fused resin is generated. Thereby the supporting lead 2 is hardly deflected when pressure of resin is applied superfluously to members in a package such as the semiconductor chip and the die pad 1, and vertical movement of the semiconductor chip and the die pad 1 can be restrained.