To solve a problem that when the motor stop time becomes longer along with the distance between a welding source and a thread feeder, when the feed starting control lines for connecting the welding source and thread feeder are cut off.

An arc-welding apparatus has a welding source and a thread feeder. The welding source includes: a feed motor control circuit; a motor-drive circuit providing the drive voltage of a motor; a first braking resistor, discharging the electromotive force produced during the stopping of the feed motor; a first commutation circuit, connecting the feed motor to the motor-drive circuit or the first braking resistor based on the cutting feed starting signal. The thread feeder includes: a second braking resistor for discharging the electromotive force; a first current detection circuit, for detecting the drive current of the feed motor or the current discharged by the first braking resistor; a motor stop discrimination circuit, discriminating the stop of the feed motor based on the polarity of the first current detection signal; and a second commutation circuit, connecting the second braking resistor to the feed motor in parallel according to the motor stop discrimination signal.