To provide a grommet having a sound-proofing part capable of being closely contacted with a sound-proofing member and capable of reversing the sound-proofing part.

The grommet 10 comprises a first cylindrical part 21, a second cylindrical part 22, a groove part 24 and the sound-proofing part 40. In this case, the part 40 is turned over, and then recovered to an initial shape. Thus, the part 40 is closely contacted with a front surface of a sound-proofing material 14. This grommet 10 also comprises an insertion auxiliary means 60 for not interfering an edge of the part 40 of a reversed state with an opening edge of a mounting hole 12.