PURPOSE: To enable to mount smoothly without generating lead bending and poor opening by a method wherein the lead part is cut to the form that it becomes the crest at the center in the lead top end width direction after cutting and then projects, using a wave cutting edge, when it is cut off from the lead integrating frame part to an independent lead.

CONSTITUTION: Positioning is so performed that each top on the mountain side of the wave part of a base 6 having the same pitch P2 as the pitch P1 between outer leads agrees with the center in the width direction of each of the outer leads 2 by a method wherein the end side part of the outer lead integrating frame 4 in the state that the top end toward the inner direction of each of the outer leads 2 of the outer lead integrating frame is sealed in the main body 1 of a package is struck and contacted on a stopper 5 which serves as the reference for positioning. After fixing by positioning, the lead can be cut to the form that the top end toward the outside of each lead project in mountaneous manner by pushing down the wave cutting edge (not illustrated) which meshes with the wave part of the base 6. When one side outer lead is cut off, and next the other side one is cut off, both side outer leads can be cut to the form that the center position in the top end width direction accurately becomes at the top of the mountain, even in the case that both side outer leads slip comparatively to slight degree.