A grommet comprises: a first cylindrical section (21) through which a group of electric wires (11) is passed; a second cylindrical section (22) shorter than the first cylindrical section (21) and surrounding the first cylindrical section (22); a base section 24 configured from a rubber elastic body which surrounds the second cylindrical section (22) and capable of being fitted to a panel opening (Pe); and annular connection sections (23, 25) for elastically connecting the first cylindrical section (21) and the base section (24). The base section (24) has a substantially elliptical shape, and the connection section (23, 25) has the sloped annular wall section (25) forming a sloped annular surface (25f) between the first cylindrical section (21) and the base section (24), the sloped annular surface (25f) being sloped in the axial direction of the first cylindrical section (21), the sloped annular wall section (25) supporting the second cylindrical section (22). The sloped annular wall section (25) and the second cylindrical section (22) are integrally provided with ribs (28) which, on both sides of the substantially elliptical shape in the direction of the major radius, extend from the axially intermediate portion (27) of the second cylindrical section (22) to the sloped annular wall section (25) and protrude from the second cylindrical section (22) toward the base section (24).