To make it possible to jet cleaning water to a rectangular cleaning room uniformly and contrive not to make cleaning unevenness by making a cleaning nozzle revolve while changing its angle of inclination in the longitudinal direction in accordance with uneven pattern of a solid section.

A guide plate 8 engaging with the upper section and the lower section of conducting pipe 4 in parallel to the side and astride a bellows pipe 41, is mounted on the conducting pipe 4. The cleaning nozzle 2 can be tilted only in the longitudinal direction. A rotor 6 is provided rotatably to the conducting pipe 4 around the conducting pipe 4. The rotor 6 is provided with an uneven pattern where recesses 62 and projections 63 repeat along the circumference of the top face 61. A slide section 24 is composed of a projecting piece 25 that projects to the upward from the underside of the side where jet holes intended for rotation of the cleaning nozzle 2 are arranged and a roller 26 that is attached to the head of the projecting piece 25, and contacts to the upper face 61 of the rotor 6 slidably.