PURPOSE: To enable a material to be dried in a short time at low a temperature by depositing the material to be dried in the form of thin film on the surface of abelt or heating rotary drum having a hood and introducing heated dry gas through one end of the hood in countercurrent to the rotation of the drum.

CONSTITUTION: A heating rotary drum immersed in a sample within a vessel 3 for the sample to be dried, is rotated thereby the sample is deposited in the form of thin film on the surface of the drum. On the drum there is provided a hood 2 spaced from the drum by a gap. Heated dry gas is supplied through a dry gas filter 10, a heater and a tube 6 to the supply port 7 of the hood 2, and is blown from the supply port 7 into the gap of the drum. The dry gas is contacted with the sample to be dried in countercurrent to the rotation of the drum and discharged from a discharge port 8. The dried sample is scratched by a scratching knife 4 and collected in a receiver 5. The drum 1 is kept at a constant temperature by circulating heated medium at a constant temperature through a line 9.