A grommet which is easy to install in a grommet hole of an automobile panel and has good water sealing ability. The grommet is assembled from a pair of grommet halves 21a and 21b, which include a pair of plastic leading members 1a and 1b, respectively, to form a leading section of the grommet; a pair of semi-disc plastic members 6a and 6b, respectively, to form an disc section of the grommet; and a pair of resilient members 12a and 12b, respectively, joining the members 1a and 1b with the semi-disc members 6a and 6b, respectively, to form a resilient section of the grommet. The resilient member shave semi-circumferential grooves 15a and 15b, which together form a complete circumferential groove 15 for receiving the edge of the panel defining the grommet hole when the grommet halves are coupled together. The disc section has a diameter larger than that of the leading section and the resilient section. The grommet halves are coupled together after wiring harnesses are placed therein, and locked by a locking mechanism provided on the outer surface of the grommet.