PURPOSE: To decrease the frequency of supplying fresh water and discarding waste water during a long time use of a self-running floor face cleaner so as to reduce the waste of cleaning operation time.

CONSTITUTION: A fresh water tank 7 and a waste water tank 12 are loaded, with an auxiliary water tank 13 interposed between the above tanks on a cleaner main body 3 adapted to clean the floor face by rotating a brush 1 while watering. The bottom of the auxiliary water tank 13 and the bottom of the waste water tank 12 are connected to each other through a shut-off valve 14, and a penetration film filter 16 is removably disposed between the auxiliary water tank 13 and the fresh water tank 7. The waste water generated after cleaning by the brush 1 with fresh water supplied from the fresh water tank through a discharge valve 5 and a discharge port 6 is accumulated in the waste water tank 12 by a vacuum pump 10 through a suction nozzle 9. When the water level in the waste water tank 12 is heightened to open the shutoff valve 14, the waste water enters the auxiliary water tank 13, so that the water level in the auxiliary water tank 13 is heightened and the waste water, from which a solid matter has been removed through the penetration film filter 14, enters the fresh water tank 7. Thus, fresh water and turbid water passed through the penetration film filter 16 are mixed to be used as washing water.