A screw feed apparatus has a screw shaft having a screw groove formed on the outer peripheral surface thereof; a nut having a screw groove formed on the inner peripheral surface thereof opposed to the outer peripheral surface of the screw shaft; a large number of rolling elements rollably interposed between the two screw grooves of the screw shaft and nut; a circulation path disposed in the nut for returning the rolling elements to their original positions; and, a deflector piece disposed in the nut for connecting the circulation path to a rolling path formed between the two screw grooves, wherein the deflector piece includes a plurality of divisional pieces respectively formed rolling element guide grooves cooperating together in forming a rolling element guide path for guiding the rolling elements to the circulation path.