PURPOSE: To weld the work by generating an arc between the end of filler metal and a torch and let the properties of build-up metal to sheet keep by letting the end of the filler metal contact the surface of the work.

CONSTITUTION: During welding work, the end of the filler metal 14 being sent to right under a tungsten electrode 12 by the operation of a feed roller 13 is contacted to the surface of the thin work 15. Then, an arc 19 is generated between the electrode 12 and the end of the filler metal 14 and the quantity of heat which the filler metal 14 receives become larger than the quantity of heat which the work 15 re- ceives, due to which the filler metal 14 melts and with the filler metal 14 being held dipped in the molten pool 16, welding is performed.