PURPOSE: To assemble and bond synthetic resin molding pieces without depending upon working precision of each part by a method wherein the synthetic resin molding pieces are fixed with photosetting resin adhesives, and synthetic resin molding pieces are positioned, bonded and fixed by irradiation of light.

CONSTITUTION: Metallic pins 7A, 7B are inserted into holes provided on base materials 6A, 6B and fixed suitably by adhesives or the like. Photosetting resin adhesives 9 are dropped on the fixed metallic pins 7A, 7B to insert synthetic resin molding pieces 8A, 8B. After the synthetic resin molding pieces 8A, 8B are positioned at the determined positions ultraviolet rays are irradiated, photosetting resin adhesives 9 are hardened and the synthetic resin molding pieces 8A, 8B are bonded and fixed. Thus, when the synthetic resin molding pieces are bonded and fixed they can be adjusted without depending upon the working precision of each part, therefore, are inexpensive and high precision mold can be manufactured.