To reduce cost without causing NC malfunction due to disturbance such as noise and without necessity of correction each time even when consumable parts in a torch are replaced with different types.

Above a work W, a processing head 13 equipped with a torch 15 is provided in a vertically movable way, and the torch 15 is integrally installed to a torch holder 39 to form a flange portion 39A. Further, the torch holder 39 is installed in a vertically movable way to a torch base 37 to form the processing head 13, and also brought into contact with the torch base 37 via a spring 47, and is provided with multiple detecting sensors 49 which detect that the torch holder 39 rises from the torch base 37. This does not cause NC malfunction, does not require correction after the torch is replaced, and can reduce cost.