To prevent a connecting fault to a pattern at the time of mounting a substrate due to a burr generated lower than a lower surface of a lead in a method for cutting the lead tip of a semiconductor element loaded on a lead frame by an operation of a punch from above to below.

Before cutting of the lead 4 tip of a semiconductor element. a groove 9 is formed by a die having a protrusion on the lower side of the part to be cut, and then the lead is cut by a punch 2. Thus, the burr will not project beyond the lower surface of the lead. Accordingly, connection fault to the pattern due to the burr in mounting the semiconductor element on the substrate can be prevented.