PURPOSE: To dry a material to be dried efficiently, by providing blades having gutter- shaped tip parts and a pheripheral wall of a circular barrel with a great number of ventilating holes.

CONSTITUTION: The drying chamber 11 consisting of the circular barrel 3 equipped with the cylindrical peripheral wall 8, provided with the front wall 9 and the rear wall 10, is installed in the cylindrical outer box 2 set in the frame 4, and the front wall 9 is equipped with the opening 9a connected to the inlet and outlet 6 of a material to be dried in the outer box 2. The inner face of the peripheral wall 8 is radiately equipped with the plural blades 12 having the tip parts 12a formed into a gutter shape at equal spaces, and the peripheral wall 8 and the blades 12 are equipped with a large number of the bored ventilating holes 14. The material to be dried is fed from the inlet and outlet 6 to the drying chamber 11, it is closed with the cover 7, the driving gear 23 is operated, and the circular barrel 3 is rotated. Simultaneously, the blower 27 and the exhauster 33 are driven, hot air is introduced through the suction pipe 29, the feed pipes 35 and 15 to the drying chamber 11 to dry the material to be dried, the air is sucked through the ventilating holes 14 of the blades 12 and the pheripheral wall 8 into the suction hole 36, and it is released from the exhaust pipe 35 to atmosphere.