To reduce the effect of a steering operation on feeling. A rack bush comprises: a bush body that is accommodated in a cylindrical housing, supports a load exerted on a rack bar while allowing the rack bar to move in the direction of an axial center O, and can be extended and retracted in a radial direction; and an elastic ring mounted on the bush body. The bush body has a mounting groove for mounting the elastic ring, the mounting groove being formed peripherally in an outer peripheral surface, and the mounting groove having a large-diameter part where the circumferential radius of a groove bottom is a first radius r1, and a small-diameter part where said radius is a second radius r2 that is less than the first radius r1. This configuration allows the formation of an elastic ring protruding part, in which the elastic ring protrudes greatly from the outer peripheral surface of the bush body, and an elastic ring embedded part, in which the elastic ring is embedded in the outer peripheral surface of the bush body.