To mount both ends of screw conveyor shafts of screw conveyor members with ease on the opposite ends of troughs.

The screw conveyor comprises a trough 1 with a U-shaped or circular cross section, coupling members 51 and 52 mounted at opposite ends 1a of the trough 1 and each having a rotary shaft 2 rotatably supported by a bearing 5b and formed with a polygonal shaft 2a at its inner end, and a screw conveyor member 4 having a screw conveyor shaft 4a with a spiral member 4b fixed on its periphery and with a polygonal bore 4c at each end. A fit connection between the polygonal shafts 2a and the polygonal bores 4c permits the coupling members 51 and 52 to couple the trough 1 and the screw conveyor member 4 into an assembled position.