PURPOSE: To obtain the dry system causing no waste water problem, to obtain the method and the device for regenerating activated carbon capable of coping with water-soluble solvent and the solvent having relatively low condensation temp. and to obtain the adsorption treating device using this device effectively.

CONSTITUTION: The heating of activated carbon 1 in the regeneration treatment is carried out by a microwave, and the circulating path 3 is provided between the activated carbon tower 2 housing the activated carbon 1 and the circulating blower 6, inactive gas g1 is circulated as carrier gas in the circulating path 3. Further, the mixed gas 2 consisting of the inactive gas g1 and the solvent gas to be desorbed is evacuated from the circulating path 3, the mixed gas 2 is cooled, the material to be adsorbed is condensed, separated and recoverd.