PURPOSE: To obtain a uniform weld zone by welding the stud of a stainless steel at opposite polarities in an atmosphere consisting essentially of an Argon gas.

CONSTITUTION: The arc is generated at the opposite polarities at which the polarity of the stud becomes plus and that of the work minus, and during this time, the arc and molten pool are shielded from the atmosphere by a shielding gas consisting essentially of an Argon gas. As a result, the arc 4 generates approximately uniformly from the approximate center of the stud 1 and the molten metal 1b at its end part 1a becomes a small particle; in addition, the molten metal 2a of the work 2 also assumes a wide and shallow tray shape. Hence, the uniform deposited metal 2b and reinforcement of weld 2c may be obtained for the weld zone after ending of welding.