TRACER CONTROL METHOD

A tracer control method whereby a tracer machining inhibit area is set and tracer machining is performed while skipping the machining inhibit area, the method including presetting a tracer machining inhibit area (TMI) and a safe level (ZL.sub.s) after taking into account the shape of a model (MDL). The method also includes moving a tracer head along the surface of the model to perform tracer machining in an area (TM), inhibiting tracer machining when the tracer head reaches the machining inhibit area (TMI), and raising the tracer head to the safe level (ZL.sub.s). After reaching the safe level the method includes moving the tracer head along the safe level to a boundary of the machining inhibit area after the tracer head reaches the safe level, thereafter performing an approach operation, and resuming tracer machining in an area (TM') after the approach is completed.