the contaminated detergent tank 17 is connected to the distiller 14 by the contaminated detergent returning line l 6 wherein a switching valve v 10 is mounted furthermore the distiller 14 is connected to the condenser 15 by a vaporized gas sending line l 7 the condenser 15 is connected to the detergent tank 11 by a condensed liquid sending line l 8 for supplying condensed and liquefied detergent in the condenser 15 to the detergent tank 11 a control unit 20 including cpu provided in the dry cleaning machine receives data output from the contamination detectors d 1 d 2 and controls the switching valves v 1 to v 10 with processing the data from the contamination detectors d 1 d 2 in the next the contamination detectors d 1 d 2 will be described with reference to fig2 a and 2b as the contamination detectors d 1 d 2 have the same structure only the contamination detector d 1 will be described herein in fig2 a the contamination detector d 1 is mounted in the detergent discharging line l 2 or the circulating line l 4 a ccd camera 23 and a light emitting element 21 as the contamination detector d 1 are placed opposite to each other sandwiching a transparent pipe 22 in the middle the light emitting element 21 the transparent pipe 22 and the light receiving section of the ccd camera 23 are covered with a shade material 24 to cut off external light into the transparent pipe 22 further in fig2 b the contamination detector d 1.