To clean a cleaner element with a central part of the supporting frame recessed into depth more than a given value.

When an air injection nozzle 4 rises and reaches lower surface of a supporting frame 12 of a cleaner element 1 and the rising of an intake tube 41 is stopped, immediately a reciprocal rotational motor 6 is reversely rotated to lower it, or the intake tube 41 is expandably formed. When the air injection nozzle 4 reaches lower surface of a supporting frame 12 of a cleaner element 1 during rising, the intake tube 41 expands and the air injection nozzle 4 temporarily stops at the position.