To provide a more secure water stop performance.

A grommet 20 includes: a wire harness insertion section; an annular depression section 44 which faces one main face of a car body panel to be arranged; a positioning section 40 which can abut on an inner peripheral section of a through hole 12 from the other main face of the car body panel; and a water stop section 60 installed in the annular depression section 44. The water stop section 60 includes: a first annular water stop section 62 which gradually expands from the annular depression face 45 to the positioning section 40; a second annular water stop section 64 which gradually expands from the annular depression face 45 toward the positioning section 40 at an outer peripheral side of the first annular water stop section 62; and an annular coupling section 66 for coupling a tip side peripheral edge of the first annular water stop section 62 and a base end side peripheral edge of the second annular water stop section 64. The annular coupling section 66 is formed to go toward an inner peripheral side of the water stop section 60 from the base end side peripheral edge of the second annular water stop section 64 and goes to the tip side peripheral edge of the first annular water stop section 62.