PURPOSE: To separately use a large nozzle and a small nozzle with no special switching means and its operation.

CONSTITUTION: The tip side of a small-diameter nozzle 12 slidable in the axial direction in a large-diameter nozzle 11 is provided protrudably from the suction port 11a of the large-diameter nozzle 11. When the small-diameter nozzle 12 is thrust into the large-diameter nozzle 11 by a preset quantity, an air hole lid is opened, and the atmospheric pressure is guided into the first air pressure chamber 15 between the large-diameter nozzle 11 and the small-diameter nozzle 12. The negative pressure is applied to the second air pressure chamber 16, the whole small-diameter nozzle 12 is pulled, stored and held into the large- diameter nozzle 11 by the differential pressure between the atmospheric pressure of the first air pressure chamber 15 and the negative pressure of the second air pressure chamber 16. The large-diameter nozzle 11 and the small-diameter nozzle 12 can be separately used by merely displacing the whole suction nozzle 1 slightly downward to thrust the small-diameter nozzle 12 into the large- diameter nozzle 11 by the preset quantity.