PURPOSE: To recover a high purity org. component from humid air by a method wherein steam is transmitted and separated through a gas separation membrane module having permselectivity to steam, and non-transmitted gas is treated with a gas separation membrane module having selectivity to org. vapor and only the org. vapor in transmitted gas is condensed and liquefied.

CONSTITUTION: Air or inert gas such as nitrogen gas containing hydrophilic org. vapor easily dissolved in water and steam are guided to a gas separation membrane module 2 having permselectivity to steam. Subsequently, non- transmitted gas is guided to a gas separation membrane module 7 having selectivity to org. vapor. The transmitted gas from the gas separation membrane module 7 is condensed to recover org. vapor in a liquid phase and the non- transmitted gas of said module 7 is discharged. As a result, the org. vapor can be condensed and liquefied in a state substantially containing no org. vapor and the org. vapor can be recovered in high purity without applying troublesome purifying treatment such as distillation.