PURPOSE: To perform efficient machining and improve workability without wasteful machining by inputting the number of machining faces of the workpieces on each pallet and the indexing rotary angle of the pallet and by performing such simple operation as making machining schedule for specifying the number of machining program corresponding to each workpiece.

CONSTITUTION: Operation is started according to the start program of each workpiece, and a pallet is returned to the datum position, and an indexing angle is operated and determined according to the surface on which the workpiece is fixed, which is specified by a machining schedule. In the next step, the pallet is rotated by this indexing angle, and the workpiece on the specified surface is set against a tool and is machined after the machining program accessed according to the machining schedule. After the machining has been completed, the program is backed to the start program, and the pallet is returned to the datum position again. Although the pallet is indexed and rotated by the angle corresponding to the next work specified in the next time, when the pallet operation is over, the next pallet exchange operation starts.