Abstract: A mold material is mounted on a mold material mount portion of a cutting/working apparatus and rotated about the C-axis serving as the rotation center while a cutting tool is driven and moved in directions X and Y. Then, a desired position of the mold material is cut with the cutting tool at a relatively formed desired cutting speed and elliptically vibrated/cut with the cutting tool, for forming a Fresnel lens molding cavity having an opening of a desired shape and a working surface (concave surface, for example) of a desired shape. The productivity of an optical component mold employed as the structure can be efficiently improved when the mold for molding an optical component such as a Fresnel lens is worked by cutting the mold material employed as a workpiece with the cutting tool in a four-spindle lathe-type cutting/working apparatus including X-, Y-, Z- and C-axes of rotation.

Abstract: In a method of working a structure, a mold material is mounted on a mold material mount portion of a cutting/working apparatus and rotated about the C-axis serving as the rotation center while a cutting tool is driven and moved in directions X and Y. Then, a desired position of the mold material is cut with the cutting tool at a relatively formed desired cutting speed and elliptically vibrated/cut with the cutting tool, for forming a Fresnel lens molding cavity having an opening of a desired shape and a working surface (concave surface, for example) of a desired shape. According to this method, the productivity of an optical component mold employed as the structure can be efficiently improved when the mold for molding an optical component such as a Fresnel lens is worked by cutting the mold material employed as a workpiece with the cutting tool in a four-spindle lathe-type cutting/working apparatus including X-, Y-, Z- and C-axes of rotation.