PURPOSE: To fix a punch firmly to a holding member and to prolong the life of a die, by welding the punch and die to respective holding members by irradiation of thermic rays of high energy density.

CONSTITUTION: After inserting a punch 1 into the groove of an inner periphery punch plate 8, the punch is fixed by a weld zone 15 welded by laser light, and fastened to an upper die holder 11. As welding using laser light is very high in energy density and only the laser spot part is melted in a short time, influence of thermal stress to other part of the spot is very little. Accordingly, positional shift of the tip of the punch 1 to the plate 8 before and after welding is very small and offes no problem practically. Therefore, conventional main members for fixing the punch 1 such as a packing plate, outer periphery punch plate and keeper ring are unnecessary. No looseness occurs in the punch 1 during using, and no breaking of edge due to positional shift occurs. The same applies to the lower die.