Abstract: A welding torch comprises a torch body having a wire guide cylinder for guiding a welding wire; an internal cylinder fitted to the torch body in such a manner as to surround the wire guide cylinder; and an external cylinder fitted to the internal cylinder in such a manner as to surround the internal cylinder. The primary interception of outside air is effected with a second shielding gas layer blown off from a second gas passageway on the outer side, and the complete interception of outside air is effected with a first shielding gas layer blown off from a first gas passageway on the inner side. Consequently, it is made possible thereby to sufficiently prevent outside air from reaching a molten pool and also sufficiently suppress the generation of an unfavorable surface oxide, thus enabling welding work to be satisfactorily practiced by using the above welding torch.