To prevent an atomizing nozzle or a nozzle frame body from falling out from a cap nut or an intermediate member under a work of gravity.

At lest one paired ring-shaped recessed parts 13, 15 mutually in the same rank or the ring-shaped recessed part and at least one hole attached thereto, are respectively provided on an inside cylinder face 12 which the cap nut 7 or the intermediate member faces to the atomizing nozzle 1 or the nozzle frame body 2, and on an outside cylinder face 14 which the atomizing nozzle 1 or the nozzle frame body faces to the cap nut 7 or the intermediate member. A shielding member 21 elastically deformable in the axial direction and (or) in the radius direction is inserted into the mutually attached recessed part 13, 15.