PURPOSE:To eliminate the need for the expensive cost of equipment and repair cost by removing a tie-bar section and fixing sections among each external lead section by heat-resistant adhesive tapes, faced oppositely to strip sections. CONSTITUTION:A tie-bar section is removed, and a heat-resistant adhesive tape such as a Teflon group heat-resistant adhesive tape 8 is carried across and fastened among a plurality of external lead sections 2 in place of the tie-bar section. When one part of such a lead frame 100 is covered with a synthetic resin 6, a transistor element is mounted to a die pad section 4 first, and an electrode for the transistor element and stitch sections 5 are wired by interval leads. The lead frame is set to a molding die for covering the synthetic resin, molded by the molding die, and cut along a chain line A-A, thus completing a transistor. Accordingly, a tie-bar cutting process is removed, thus eliminating the need for expensive facilities and repair cost with the formation of the tie-bar cutting process, then mass-producing semiconductor devices extremely economically.