PURPOSE: To provide a lead frame structure which does not provide any chip when a tie-bar is cut and also a high cutting precision for cutting of tie-bar and a method of cutting the same.

CONSTITUTION: A tie-bar 2 of lead frame 4 includes almost the center area 2b of both leads 3 coupled which is narrower than the lead boundary area 2a. The tie-bar is cut only at the center area 2b and is then separated to both sides from this cutting area. Thereby, since any chip is generated and the cutting area is narrower than the other tie-bar portion, if the cutting position is deviated, the narrower center area may be cut easily, requiring no higher precision for the cutting operation.