PURPOSE: To quicken tapping work, by mounting many tapping heads on a turret to make various tapped holes by a single machine.

CONSTITUTION: A servomotor 15 is rotated to turn a turret 8 so that a tapping head 7 appropriate to a preparatory hole made in a plate W is placed in front. The turret 8 is secured by an indexing pin unit 21. The plate W is held down by a plate pusher 44. An air cylinder 37 is expanded by one stage. A gear 29 is engaged with a gear 35 for driving the tapping head 7. A motor 33 is driven to turn the rotary shaft 24 of the tapping head through the gear 35 to rotate a tap 41 to cut a prescribed screw in the preparatory hole.