PURPOSE: To absorb the impact of the case of abutting a torch electrode to a conductor and activate the torch electrode without damaging it by fitting the conductor to a base board via an elastic body.

CONSTITUTION: In case of a main welding the torch electrode 9a of a torch 9 is abutted to the above of a conductor 2. It is abutted to the other end part 3b side of a supporting plate 3. In this case, the impact cue to the abutting to the conductor 2 of the torch electrode 9a is absorbed with the contraction of a spring 7 with the other end part 3b of the supporting plate 3 being pushed to the lower part. An arc 11 is caused at the moment when the torch electrode 9a is apart from the conductor 2 and heated to become in its activated state. The heating means 15 consisting of a heat wire 15a is arranged inside a bottomed cylindrical body 15 and heated with noncontact by inserting the torch electrode 9a. In these ways, the torch electrode 9a can be activated by heating it effectively without damaging it.