A TIG welding method is usually carried out in a manner that a tungsten electrode is inserted into a weld groove portion of a member to be welded, an electric voltage is applied to a current conducting portion provided for the tungsten electrode while flowing a shield gas means to thereby generate an arc between the tungsten electrode and the member to be welded to form a molten pool of the member, a welding wire is inserted into the molten pool, and a welding torch is then operated to perform a welding process. In the improvement of the TIG welding method, the shield gas means is composed of an inner shield gas flowing from a periphery of the tungsten electrode to a front end thereof inserted into the weld groove portion of the member to be welded and an outer shield gas flowing towards the weld groove angle from an outside of the inner shield gas to prevent the molten pool from being oxidized and to prevent oxygen in air from being involved. The TIG welding torch for carrying out the method is specifically provided with the inner and outer shield gas flow means, and further provided with a central shield gas flow means.