PURPOSE: To maintain a specified spacing between torch nozzle and a material to be cut and to finish the cut surface to a specified condition by supporting the nozzle on the surface of said material via a mechanical balancing means.

CONSTITUTION: A torch nozzle 3 is stably supported on the surface of a material 9 to be cut by means of supporting legs 11 via rollers 10. The nozzle 3 is provided freely vertically slidably to a cutting head 1. The head 1 and the legs 11 are connected alongside the head by means of a cylinder device 12 for balancing. The legs 11, i.e., the nozzle 3 are held under weight balance through a rod 16 by the force of springs 17, 18 built in the cylinder 13. Even if the surface of the material 9 in the cutting position is curved, the rollers 10 roll along such surface and the spacing between the nozzle 8 of the nozzle 3 and the material 9 is maintained constant.