To prevent resin crack in a lead frame for semiconductor device with slits formed in its island, and enhance the reliability of the lead frame, by sticking a tape to the slits.

A tape 2 is stuck to the entire underside of an island section 1 with slits 8 formed therein using adhesive 3 to cover the slits 8. Cu or an iron-nickel alloy is used for lead frame material, and the slits 8 are formed in the island section 1. The shape of the slits is so designed that the corners of the island is latticed, and the slits 8 are formed in the area where a semiconductor chip is bonded. The tape 2 of organic matter is stuck to the entire underside of the island 1 using the adhesive 3 composed of thermosetting resin. Thereby difference in thermal expansion between the tape and the resin which is encountered during resin shrinkage can be reduced, and thus the island section 1 be prevented from cracking owing to the slits 8. Further, degradation in the reliability of the semiconductor chip connection can be avoided.