PURPOSE: To easily remove the attachments such as iron powders attached to the welding wire and to effectively prevent attachments from again attaching to a welding wire by demagnetizing the welding wire.

CONSTITUTION: The welding wire cleaning device 14 consists of a demagnetizing mechanism 15 and an air suction mechanism 16. The magnetizing mechanism 15 is provided with an almost cylindrical demagnetizing coil 18 and an insertion hole 20 into which the projected welding wire 7 is inserted freely insertably and extractably from the nozzle part 11 of a welding torch 4 is formed thereon. The air suction mechanism 16 is provided with a supporting cylinder 23 and a suction device 25. The air in the demagnetizing coil 18 is sucked from the welding wire 7 insertion side and an opposite side through the communication hole 26 of the supporting cylinder 23 by operation of the suction device 25.