To separate gas containing no flux component from a gaseous mixture containing the flux component and recover the flux component. Water vapor generated in a separation unit is cooled by a condensation unit, recovered as water droplets, and reused. Provided are a first water spray unit (20A) that sprays water into a gaseous mixture containing the flux component; a separation unit (10) that includes an introduction port for introducing the gaseous mixture into which water is sprayed from the first water spray unit (20A), the separation unit using a swirling flow to separate the flux component from the gaseous mixture; a second water spray unit (20B) that forms a precipitation flow inside of the separation unit; and a condensation unit (17) that cools water vapor generated in the separation unit (10) to change the water vapor to water droplets, thereby removing the water vapor.