Through the present invention, the load of a torch (16) applied to a welding workpiece (W) in a touch start method is reduced, and stability is significantly enhanced. A welding head (10) has a rigid straight-advancing movable part (12), an elevator drive tower (14) for moving the straight-advancing movable part (12) straight forward in the vertical direction, and a torch (16) mounted on the straight-advancing movable part (12) so as to be able to move in the vertical direction. One end part of a balance arm (28) rotatably attached to a multi-purpose support part (22) of the straight-advancing movable part (12) is connected to a torch body (30), and a balance weight (98) is attached to the other end part of the balance arm (28).