A wire feeding unit includes a driving motor; a driving roller which rotates by a driving force of the driving motor; a plurality of driven rollers arranged such that outer circumferential surfaces thereof are positioned on a same line; a belt which interlocks the driving roller and the plurality of driven rollers and is brought into contact with a wire, which is drawn into a side of the driven rollers, on a side of the plurality of driven rollers; and a plurality of idlers which support the wire on a side in which the wire and the belt are in contact with each other and assist feeding of the wire along a feeding direction of the belt in a free-rotation state.