PURPOSE: To recover a solvent at high accuracy by providing a stage for coarsening fine water droplets with a fibrous sheet at the interval until the solvent is reutilized after a specific gravity difference separating stage.

CONSTITUTION: A solvent in a dewatering tank 20 is separated with specific gravity difference by a water separator 22 and a coarsening stage of fine water droplets is provided in a dewatering tank line. Fine water droplets having 0.1-50μm diameter are made coarse water droplets not smaller than 0.1mm by coarsening. Therefore fine water droplets are coarsened by a fibrous sheet which is formed of fiber of 0.1-10μm diameter of filament as a main body and has 30-90% porosity, 0.1-70mm thickness and ≥35dyne/cm critical surface tension of fiber surface. As fiber constituting the fiber sheet, polyethylene terephthalate and polyethylene terephthalate adipate, etc., are utilized. Thereby deterioration of quality of washing material is prevented.