PURPOSE: To obtain a device, wherein a tool head can be simultaneously exchanged by a simple structure, by arranging a tool head exchanger, in which hook parts opposed to both the tool heads are provided in both side surfaces, between a turret head and a magazine.

CONSTITUTION: A tool head exchanger 3 is arranged midway between a work machine l and a magazine 2. After a tool head 5A is unclamped relating to a holding surface 6 by actuating a tool head clamp mechanism, hook members 79 of tool heads 5A, 5B are hooked by hook members 77 to lift a turret head 45 and the magazine 2 by lifting an exchanger 70. The exchanger 70, when it reaches a lift limit, is 180° rotated to exchange positions of the tool heads 5A, 5B. A hook member 77 is dislocated from the hook member 79 by lowering the exchanger 70 to deliver both the tool heads 5A, 5B to the magazine 2 and the turret head 4, and the tool head 5B is clamped relating to the holding surface 6 by returning the exchanger 70 to a lowering down end.