To avoid disadvantage in the start of machining is such a state that a workpiece does not conform to a machining program by additionally providing a check process discriminating the conformity of the set workpiece and a corresponding work program.

Between a program setting process for setting a machining program corresponding to a workpiece 1 set to a jig A and a machining process for working of the workpiece 1 in a work machine B based on the preset machining program, an inspecting process discriminating whether the set workpiece 1 and the preset machining program are conformed or not is carried out, the process is transferred to the machining process only when conformity is discriminated.