PURPOSE: To regenerate activated carbon and to form gases contg. SO2 at a high concn. by bringing heating gases into contact with the SO2 adsorbed activated carbon which glides successively on plural inclined racks which are provided partly superposedly an specially in vertical directions.

CONSTITUTION: Activated carbon 15 adsorbed therein with SO2 is supplied from a storage tank 13 provided in the upper part of a heater 11 into the heater 11 through a supply valve 14. The activated carbon 15 glides successively in uniform thickness on racks 12 and moves from the upper part to the lower part. During this time, heating gases are blown through the gas inlet 16 in the upper part of the heater into the heater 11 and contact directly with the falling activated carbon 15, and descend by passing through the spaced clearances between the racks 12. Here, the heating gases are brought into contact uniformly and efficiently with the carbon 15 by the louver effect of the racks 12 or by baffle plates 17. The carbon 15 which is heated and is desorbed of SO2 is dischrged at prescribed rates through a discharge valve 18 via a cooler 19 by means of a roll feeder 20. The heating gases contg. the desorbed SO2 are discharged through a discharge port 21.