To enhance waterproof performance at the part for fixing a grommet in an automobile.

A grommet 10 is filled with a water stopping agent and a disc- like water absorbing member 15 having a central hole for passing a wire harness is brought into contact, on one side thereof, with the entire exposed surface of the water stopping agent layer 14 and, on the outer circumferential surface thereof, with the inner circumferential surface of the grommet. The disc is exposed, on the other side thereof, to the outer air in the grommet so that the water intruded to the indoor side is absorbed and evaporated thus preventing the water absorbing member from being saturated.