PURPOSE: To perform mounting stably in a wall with no labor required for execution work.

CONSTITUTION: A ventilating pipe 1 is constituted of a main unit 1a formed almost cylindrically with both ends opened and a mounting base 10 integrally provided in a peripheral surface of the main unit 1a. In a peripheral part in the vicinity of both opening ends of the main unit 1a, a plurality of streaks of ring-shaped notches 2 in parallel to an opening surface are respectively formed. In the mounting base 10, a supporting piece 12 is formed to rise up from a rectangular flat plate-shaped base 11, to mount the main unit 1a on the supporting piece 12. In a short side in both ends of this base 11, an insertion hole 13 for inserting a mounting machine screw 19 is provided, and a pair of notched grooves 14 are provided so as to interpose this insertion hole 13. The mounting machine screw 19 is inserted to the insertion hole 13 or the notched groove 14 of the mounting base 10 stopped by a screw to a stud, and the ventilating pipe l is firmly stopped to the stud.