To effectively prevent the floating of a mat by withstanding the jetting pressure of high pressure cleaning water and to cope with the change in the thickness of the mat.

An upper side roller 523 constituting a pull-in roller 52 is provided movably relatively to an under side roller 524. A rotary drum 2 for placing the mat M pulled by the pull-in roller 52 on an outer peripheral surface provided with a water passing opening and moving the mat is provided and a jetting nozzle 35 for jetting cleaning water toward the outer peripheral surface is provided at the center of the rotary drum 2. A press board 9 positioned above the rotary drum 2 is supported by an axis member 17 and is pressed to the under side roller 524 by giving the dead load from the tip part 93 of the press board 9 to the upper roller 523. A spring board 95 is provided, the base end is fixed to the tip part 93 of the press board 9 and the tip end of the spring board 95 is placed on the outer peripheral surface of the rotary drum 2 and is in elastically contact with the upper surface of the transported mat M.