To provide a cut polymer automatic feeder which stably automatically feeds the fixed amount of cut polymer cut in a rectangular shape to a grinding machine without relying on manual operation of an operator.

The cut polymer automatic feeder feeds the rectangular cut polymer to the grinding machine, and includes: a hopper 11 in which the cut polymer is thrown; a stirring means 3 for stirring the cut polymer thrown in the hopper; and an engaging/delivering means 4 in which a plurality of driving rolls 14 having engagement blades are horizontally provided, the engagement blades are engaged to deliver the cut polymer from the hopper to the grinding machine. The stirring means 3 is constituted to vertically oscillate an arm arranged above the discharge port of the hopper 11 with a driving means 16 in the hopper. The engagement blade includes a long blade and a short blade that are radially projected with a central focus on a roll shaft of the driving roll 14. The long blade and the short blade are alternately arranged in the circumferential direction of the roll shaft.