To complete a CAM operation without requiring manual operations for generating NC data, which enables accurate and rapid machining, through organized integration of each means and increase in the speed to determine conditions. To achieve this, the present invention comprises a shape input means 1 for inputting a shape of a work piece; a machining planning means 2 for planning a machining method of the work piece; an NC data generating means 3 for generating NC data used for machining the work piece; an NC data verifying and editing means 4 for verifying and editing the NC data; and an NC data output means 5 for outputting the NC data, wherein the NC data is integrally generated based on the shape data of the work piece as the work piece successively passes through these means.