To efficiently recover a volatile organic material without bringing disadvantage in the aspects of cost, resource saving, waste generation and energy saving.

When discharging organic solvent vapor to the atmosphere through an exhaust duct produced in a device using an organic solvent by heating, the inside of the exhaust duct is cooled. As a result, the volatile organic solvent is liquefied (condensed) to efficiently remove the organic solvent from a gas. The method is applied, for example, for a drying device for a semiconductor wafer. The wafer drying device is provided with a heating mechanism for housing the organic solvent and heating the organic solvent and has an organic solvent vessel, in which the wafer is exposed to the organic solvent vapor, in an upper side space and the exhaust duct for discharging the organic solvent vapor produced in the organic solvent vessel to the atmosphere and a cooling mechanism is provided in the exhaust duct.