Exhaust air from a coater drier is sent to a desorption zone of a VOC concentration rotor. Air which comes out of the desorption zone is sent to a heat exchanger and cooled, the cooled air which comes out of the heat exchanger is sent to a cooling coil which carries out VOC concentration recovery. Air which comes out of the cooling coil is sent to an absorption zone of the VOC concentration rotor. Air which comes out of the absorption zone is sent to the heat exchanger and heated. The heated air which comes out of the heat exchanger is sent to a heating coil to be used as supply air for a coater drier. A heat pump can be used for the cooling coil which carries out cooling condensation of the organic solvent and the heating coil which heats purified air as air supply for the coater drier.