A nut feeding apparatus for feeding a weld nut to an upper electrode of a resistance welding machine, whose size and production cost are reduced, is disclosed. The apparatus comprises a piston rod, a tension rod, a tube, a link mechanism and a nut chuck. When the piston rod is in a most retracting state, an upper surface of the nut chuck becomes substantially flush with a lower portion of an opening of the tube. While the tension rod is at a stop in a most advancing state and when the piston rod further advances, the link mechanism rotates around a rotation axis at a tip of the tension rod, and thereby, the weld nut held by the nut chuck moves to a feeding position of the weld nut in the upper electrode.