PURPOSE: To clean a glass window on an upper curved surface part and a vertical surface of a building efficiently by lifting or lowering the body of a cleaning apparatus by winding a wire rope while the body of the cleaning apparatus is sucked securely on the glass window by a vacuum cup connected to a suction fan.

CONSTITUTION: When a glass window 6 on an upper curved surface part of a building is cleaned, a wire rope 4 and an operation cable 81 provided on a curved surface cleaning truck 84 is connected to a corridor set along a top part of the building. Under such a condition, the body 1 of a cleaning apparatus is caused to be sucked on the glass widow 6 by a vacuum cup 9 and lifted or lowered through a running roller 7 by winding the wire rope 4 into or unwinding it out of the winch 5. A cleaning device 11 is made to slide horizontally in a state in which a longitudinally sliding base 10 provided on one side in the direction of moving the body 1 of the cleaning apparatus is overhung and then, after the longitudinally sliding base 10 is withdrawn, the glass window 6 is cleaned by making the cleaning device 11 slide horizontally.