This TIG welding device has: a unit-type device main body (10) having a DC-type welding power supply circuit, a control circuit, and a variety of drive circuits, etc., housed therein; and a welding head (12) that performs TIG welding using a touch-start method, on a section to be welded in a base material upon an electrical component supporting body (S) under the supply and control of force from this device main body (10). In the welding head (12), a linear drive member (34) is joined via a raising/lowering support shaft (32) to a raising/lowering drive unit for a raising/lowering tower (30). A torch (22) and a clamp electrode (24) are vertically attached to this linear drive member (34) so as to be integrally movable and to be separable. As a result, high quality arc welding whereby two members (base materials) are held by a clamp and welded can stably and reliably occur.