Two rotors 18a, 18b each housing a honeycomb structure 25 carrying an absorbent is driven for rotation by a common motor 19. Partitioning members 17 define an absorbing zone S and a recovery zone U in the rotor depending on the angular positional relationship between the partitioning members 17 and the rotor corresponding thereto. In the absorbing zone S, the absorbent removes moisture and organic matters from air passing therethrough. In the recovery zone U, recovery of the absorbent deteriorated by absorbing the moisture and the organic matters is preformed by using heated dry air. Air sucked from a transfer space 10 of the processing system sequentially passes through the absorbing zones of both the rotors via a circulation passage 20, thereafter returned to the transfer space. A part of clean dry air having passed through the absorbing zones of both the rotors is supplied into an exhaust passage 21, and is heated by a heater, and passes through the recovery zones of both the rotors.