To provide a grommet which has large diameter parts on both side attached to a pair of penetration holes on panels and a plastic inner integrated into a large diameter part, and can reduce the area of the penetration hole.

A plastic inner is divided into two bodies, and the two divided bodies are connected freely foldably by a hinge. When the plastic inner passes a first hole, the plastic inner is folded, when the plastic inner passes a second hole, the plastic inner is restored to annular-type shape and is fit to the rim of the second hole.