A rack bush (10), which is part of a rack and pinion type steering system and supports a rack shaft (8) in which rack teeth (15) are formed at one circumferential portion, includes a bush main body (16) and a rigidity reducing portion (18). The bush main body has an annular shape into which the rack shaft is inserted. The bush main body is divided, in a circumferential direction, into two portions including a rack teeth-side portion (22) located on the same side as the rack teeth in the circumferential direction and a back face-side portion (23) other than the rack teeth-side portion. The rigidity reducing portion is provided in the rack teeth-side portion, and makes a rigidity of the rack teeth-side portion lower than a rigidity of the back face-side portion.