In order to provide a surface treatment device for treating a surface of a workpiece which is operable simply and safely, it is proposed that the surface treatment device include the following: a work region in which the surface of the workpiece is treatable; a flow guiding device by means of which a gas stream is guidable through the work region; a solvent separating device for separating off solvent from the gas stream that is guided through the work region, wherein the solvent separating device is configured to be put selectively in a separating condition or in a rest condition, wherein, in the separating condition, the solvent separating device separates off solvent from the gas stream.