PURPOSE: To suppress clogging of powder nozzle and to always satisfactorily supply powder material.

CONSTITUTION: An injection nozzle 14 of plasma arc is formed in the center of a torch head 16, with five powder nozzles 18 formed each obliquely toward the center at prescribed interval in the circumferential direction surroundedly outside the injection nozzle 14. The opening part 18a at the lower face of the torch head 16 in each powder hole 18 is set so as not to face against other openings in the feeding direction of the powder material from the opening part 18a across the injection nozzle 14. Consequently, after the powder is fed into plasma arc from the opening part 18a of each powder nozzle 18, the opening part 18a is protected from being clogged by the reflected powder sprung back to the torch head 16 side without being thrown in the molten pool.