A cleaning apparatus is generally composed of a suction unit provided with a suction source, a suction nozzle equipped with a suction port adapted to suck dust or like from a surface to be cleaned, a suction hose connected at one end to the suction nozzle and connected at another end to the suction unit, a low-center-of-gravity support member provided for the suction hose so as to serve as a fulcrum when the suction hose is bent and deformed, a wire member supported at a distal end by the suction nozzle and arranged along the suction hose, and a control unit used to bend and deform the suction hose by manipulating the wire member with the low-center-of-gravity support member serving as a fulcrum. This cleaning apparatus is specifically usable for a bottom surface of a reactor pressure vessel.