To improve steering feeling of a steering mechanism having a rack-pinion structure.

Spherical bodies B1, B2, B3 respectively rolling in recessed grooves 1G1, 1G2, 1G3 are allowed to intervene between an internal surface 3a of a through-hole of a bush 3 and the recessed grooves 1G1, 1G2, 1G3 provided in an outer peripheral surface 1e of an terminal end part of a rack axis 1. The number of the spherical bodies B1, B2, B3 is three. The outer peripheral surface 1e of the terminal end part of the rack axis 1 is supported by the three spherical bodies B1, B2, B3 with respect to the bush 3. The spherical bodies B1, B2, B3 are respectively provided so as to rotate on its axis on an inner surface of each position that divides the annular bush 3 into three portions in a circumferential direction.