A welding apparatus includes: a welding machine having a lower arm member, an upper arm member, and electrodes configured to advance and retreat; a robot device to which the welding machine is mounted; a support member including a vertical member substantially in a vertical direction, and a horizontal member substantially in a horizontal direction. The vertical member is mounted on one of the lower arm member and the upper arm member at a position away from the electrode of the one of the lower arm member and the upper arm member; and a parts-feeding device mounted to the horizontal member and configured to feed parts to the electrode.