PURPOSE: To eliminate irregularity and dripping of droplets due to dew condensation and to process a wafer with uniform organic solvent vapor by making a conduit for introducing the vapor into a wafer processing chamber in double structure, and constructing in such a manner as to pass the vapor to an inner tube and wafer for regulating temperature to an outer tube.

CONSTITUTION: An organic solvent 2 in a bubbling tank 1 is bubbled with nitrogen through a nitrogen bubbling nozzle 3, and organic solvent vapor 4 is generated in the tank 1. The vapor is introduced by an organic solvent vapor conduit 5 to a wafer processing chamber 6 to process wafer 10. A conduit 5 is passed in an outer tube 9 through which water being a medium for regulating temperature held at a predetermined temperature by a unit 7 via a temperature regulating water tube 8 on the way to hold the temperature of the vapor passing the interior constant.