PURPOSE: To reutilize sewage and to perform continuous cleaning over the long period of time by providing a communicating path between a fresh water tank and a sewage tank in a cleaning machine for sucking the sewage on a floor surface and recovering it to the sewage tank while leading out fresh water inside the fresh water tank near a rotary brush.

CONSTITUTION: While the fresh water inside the fresh water tank 7 on a truck 3 is led out through an delivery valve 5 and a sprinkler pipe 6 near the rotary brush 1 provided on the lower surface of the truck, the sewage on the floor surface is sucked by a water sucking nozzle 9 by the action of a vacuum pump 10 and recovered to the sewage tank 12. Then, the communicating path is provided on a position where the water amount of the sewage tank 12 becomes 1/2 of the amount when it is filled between the fresh water tank 7 and the sewage tank 12. A check valve 18 is provided on the side of the fresh water tank 7 of the communicating path and a filter 17 is provided on the side of the sewage tank 12. Thus, when the vacuum pump 10 is stopped, the check valve 18 is pushed open by water pressure and the sewage is moved from the sewage tank 12 to the fresh water tank 7. At the time, the sewage is filtered by the filter 17 and reutilized.