PURPOSE: To unmannedly machine high-precision parts without reducing productivity while controlling the work temperature by inputting the time required for work temperature control in advance for each work, and planning the machining schedule via the calculation minimizing the machining waiting time generated for the work temperature control.

CONSTITUTION: The time required for the work temperature control of each work is obtained in advance and inputted to a work conveyance control device 10, and the work machining sequence is determined and numerically controlled (NC) machine tools 1-4 are automatically selected by the calculation minimizing the waiting time of the NC machine tools 1-4 from the time required for the cut machining of each work and the inputted time required for the work temperature control. The actual cut machining time of the NC machine tools 1-4 is increased, and high-precision parts can be unmannedly machined with high efficiency while the work temperature is controlled.