PURPOSE: To provide a machining method, by which a high quality through-hole or a high quality internal thread can be machined at low costs and compactification can be carried out, for a through-hole and an internal thread in a sheet metal workpiece with bending work and to provide a sheet metal workpiece with vending work.

CONSTITUTION: A machining process for sheet metal workpiece having bending work is carried out in the following order of perforating, cutting and separating, tapping, and bending, and waste holes A.2 of the predetermined dimensions are arranged on the center line 3 for bending position while setting a point of intersection with the center line 4 of through-hole or internal thread hole 1 position to be set as the center, and then, bending is carried out, so that a high quality through-hole or a high quality internal thread 1 can be obtained without any deformation, and compactification can be carried out.