To prevent the intrusion of noise from the outside and the intrusion of outside smell with the noise, and to ensure comfortable interior comfortability, by perfectly insulating a ventilating passage and a ventilating port by a shielding material, in a ventilating device using a sound insulating material having excellent sound insulating performance.

A ventilating means is formed by a receiving member 6 provided on a periphery of a ventilating passage opening portion 3 of an interior side B and having an annular first outer peripheral surface 6a, and a main body member 5 having an annular second outer peripheral surface 15 detachable received and attached by the first outer peripheral surface 6a of the receiving member 6. On the main body member 5, a main body side insulating material 130 formed into a size blocking the ventilating port 3 surrounded by the receiving member 4, and an opening/closing operation means 11 moving so as to close/open the ventilating port 3 by joining/separating the main body side insulating material 130 to/from the receiving member 4, are provided.