PURPOSE: To improve the operation rate of a machine and execute machining with high accuracy by constituting the title automatic exchanger with a dividing moving mechanism, a clamp base, a table and a tool holder feeding in/out device.

CONSTITUTION: A dividing moving mechanism 4 moves a pallet changer 1 so as to dividingly position a desired pallet 2 having chaser 3 mounted thereon at a predetermined position. A cutting tool holder feeding in/out device 5 feeds the positioned pallet 2 onto a clamp base 6 side and fixes it thereat. The movement of the clamp base 6 in X and Z directions effect the machining of a workpiece held by a main shaft. The tool holder feeding in/out device 5 puts the pallet 2 after use into the pallet changer 1, thereby terminating the automatic exchange of a tool holder. Therefore, a preparatory time can be remarkably improved and the machining with high accuracy can be executed.