PURPOSE: To remove malodor evolved at the time of drying sludge, etc., by sucking the malodor using a water ejector and mixing the malodor with water.

CONSTITUTION: In the case of drying sludge, etc., sludge is thrown to a drying container 1 and steam is supplied from a steam supplying pipeline 12 connected with a steam jacket 2. While being stirred, the sludge is heated and water is evaporated. Drain produced in the steam jacket 2 is discharged through a drain discharging pipe 14. In the water ejector side, an ejector pump 10 is driven and water in a water tank 9 is circulated in the way that the water is led to pass a heat-exchanger 11, sent to the water ejector 8, and returned to the water tank 9. Pressure is reduced in the water ejector part 8, the malodor evolved in the drying container 1 and steam pass a deodorizing pipeline 7 and the resultant malodor and steam are sucked to the water ejector part 8. The sucked malodor and steam are mixed with water in the water ejector 8 and absorbed in water by bubbling in the water tank 9 to carry out deodorization.