PURPOSE: To advance weld beads rectilinearly during welding and perform stable welding by giving a specific bending set to a welding wire and loading the wire in a pail pack.

CONSTITUTION: A welding wire 4 fed from a wire supplying sources is given a bending set of 250W2,500mm diameter by a bending set applying mechanism 5 consisting of plural rollers. The wire is pulled by a wire supplying mechanism consisting of a wire take-off capstan 6 and a press roller 7 and is inserted into a rotary flyer 8 assuming a flyer mechanism through its inlet 10 and is loaded through a rotating outlet 11 into a pail pack 9. Since the top end of the wire is fixed to the wire feed mechanisms 6, 7 and the bottom end to the top end surface in the wire stacking part W in the pack 9, a 360° twist in one rotation of the flyer is given to the wire. The deformation that the wire receives is only the deformation within its elastic limit, and the wire is contained in the pack 9 while incorporating only the prescribed plastic bending set.