Cleaning Robot is equipped with two suction disks and two air cylinders among the disks to expand and contract the distance between the disks. Each suction disk is equipped with one air cylinder to go in and out the roller unit in the direction of the surface. The two suction disks are connected with the suction pump by the suction hose. When the suction pump is started, the disks adhere to the surface powerfully by acting of the differential-pressure of the fluid. Each roller unit and each air cylinder are automatically controlled by the programmable control unit and the sensors.