PURPOSE: To perform welding through an opening, to perform welding of a clamping part with high alignment accuracy and to improve assembling accuracy by providing the opening for laser beam irradiation on a clamping pawl.

CONSTITUTION: A place to be welded of works 2 and 3 is clamped by the clamping pawl 1a of a clamping member 1 and a head 5b of laser beam welding equipment 5 is moved and positioned. When a laser beam R is irradiated, the place to be welded of the works 2 and 3 can be spot-welded through the opening 4 of the clamping pawl 1a. Since the place having the highest accuracy pressed by the clamping pawl 1a is welded, the alignment accuracy by the clamping member 1 can be held as it is. In addition, it is possible to make a fitting hole for a subsequently fitted part and boring with high alignment accuracy can be carried out by executing boring by pressing with the clamping pawl 1a.