PURPOSE: To filter the gas discharged from a process using an org, solvent by org. solvent adsorbing activated carbon to discharge the same and to recover the org. solvent adsorbed on the activated carbon.

CONSTITUTION: After org. solvent-containing exhaust gas 1 is filtered by activated carbon to be discharged, steam is supplied to the activated carbon having the org. solvent adsorbed thereon to regenerate the activated carbon and org. solvent-containing steam is condensed and liquefied to form a condensate 11 which is, in turn, subjected to oil-water separation to retilize the org. solvent sparingly soluble or insoluble in water. Separated water containing a water-soluble org. solvent is decomposed by a org. solvent decomposition means 27 to be subjected to purifying treatment.