A grommet is secured to a wire harness inserted in an opening of a panel. The grommet is fitted in the opening and mounted, thereby supporting the wire harness in the panel, The grommet has: partition walls covering the periphery of the wire harness and forming a sound-blocking space around the wire harness; and a sound-insulating wall formed inside the sound-blocking space so as to intersect the longitudinal direction of the wire harness.