To easily conduct a position instruction by mounting an illumination appliance in a slit arranged to a tip of a nozzle of a welding torch,

A slit 13 is arranged to a tip of a nozzle 10 of a welding torch, an illumination appliance 14 is mounted into the slit 13, Further, a tube 16, which is made of a transparent, soft material and is thinner than the nozzle 10, is mounted to the tip of the nozzle 10. Thus, a light L of the illumination appliance 14 is not disturbed with the nozzle 10 and the tube 16 and illuminates the inside/outside of the nozzle like a tip 21 of the tube 16 and a work 17. A position instruction work to an arc welding robot is done in a short time. Further, by forming the tube 16 with a soft material, when the welding torch collides with the work 17, its impact is absorbed by deformating the tube 16 and is prevented to be transferred to the welding torch, the damage of the welding torch is prevented.