A grommet comprising: a panel mounting portion which is mounted on an opening of a panel and has a large-diameter hole for loosely receiving a wiring harness; a wire receiving portion which is formed axially integrally with the panel mounting portion and has a small-diameter hole for closely receiving the wiring harness; the large-diameter hole being communicated with the small-diameter hole such that the wiring harness is inserted through the small-diameter hole and the large-diameter hole in an insertion direction oriented from the small-diameter hole to the large-diameter hole; and a plurality of ribs which are provided in the large-diameter hole so as to extend in parallel with the insertion direction of the wiring harness.
