A circulation-air generating unit directly generates circulation air that flows along a surface of a cleaning tank. The circulation air is applied to cleaning medium accumulated on the cleaning tank from a direction orthogonal to a direction of face of the cleaning medium to deliver and flow up the cleaning medium. The cleaning medium is flown up inside the cleaning tank by the force of the circulation air. The cleaning medium flowing inside the cleaning tank collides with a cleaning target object by high-velocity air supplied from a cleaning-medium accelerating unit to remove dust on the cleaning target object.