A screw conveyor type drying apparatus comprises a plurality of hollow drive shafts (9a, 9b) each having a plurality of feed vanes (16) provided thereon along an imaginary helix positioned on the outer peripheral surface of the drive shaft, a driving device (11-15) for driving the drive shafts so that adjacent drive shafts are rotated in mutually opposite directions, the plurality of drive shafts being rotated in mutually opposite directions whereby a material to be dried is conveyed, and a device for feeding heating fluid into the hollow portions of the feed vanes through the hollow portions of the drive shafts, whereby the material coming in contact with the feed vanes during conveyance is heated and dried.