PURPOSE: To sufficiently carry out the removal of contaminants, such as oily components, sticking to the surface of wash having fine gaps by providing the device with a fresh liquid supply device for separately impregnating the wash with a clean org. solvent and supplying this solvent to the wash after solvent circulation.

CONSTITUTION: The stages of activating a pump 16 to supply the solvent in an atomized form to the wash 4 from the upper part of a washing tank 1 in the state of closing cocks 13 and 15 for connecting a contaminated liquid vessel 7, a fresh liquid vessel 8 and the tank 1 and opening cocks 12 and 14 for connecting a solvent vessel 6 for circulation and the washing tank 1, then circulating the solvent to the solvent vessel 6 for circulation are repeated a prescribed number of times. The opening and closing of the cocks 12 to 15 are then reversed and the wash 4 is impregnated with the clean solvent in the fresh liquid vessel (fresh liquid supply device) 8 and is supplied therewith by the operation of the pump 16. The solvent in the washing tank 1 is thereafter discharged and removed and the wash 4 is heated and dried by a heater 18 in the state of maintaining a reduced pressure in the tank 1 by the vacuum pump 16, by which the impregnating solvent substituted with the oil and fat components sticking to the surface of the wash 4 is splashed away and finished.