PURPOSE: To make the setting of welding conditions easier and more accurate by storing the welding data of a welding sequence, the numerical value in the sequence, etc., in an IC card, inserting those to a reader, reading the welding data, transferring them to a control part and outputting the necessary signal.

CONSTITUTION: The welding data fed from a torch switch 35, the switch 36 of a shielding gas flow, an output setter 37, a fine adjuster 38, display changing over switch 39 and an IC card reader 60 are inputted to an MPU 43 via an input and output part 41. The MPU 43 performs operation and control based on the inputted signal, a ROM 44 stores the processing means of the MPU 43 and a RAM 45 stores the data. A wire electrode 49 is fed to a base metal 48 and voltage and current are fed from a welding electrode 52 according to the signal of the MPU 43. The voltage feedback control and current feedback control are executed according to the welding method by a voltage detector 55 and current detector 54. Consequently the welding conditions setting becomes easy and the work control can be surely executed.