PURPOSE: To prevent the increase of a steering operation force at a large steering angle by providing a slant that is extending in the axial direction, along a rack surface on which a pressing body is pressed and deep at the center and narrow at both ends, and energizing the pressing body onto the slant using an elastic body.

CONSTITUTION: When a car runs straight, a pressing body 10 receives the elastic force of a spring 12 and is pressed at the central position (A) of a groove 16. When a pinion gear 8 is revolved to turn a car, a rack 3 is moved to one axial direction. When the travel of the rack exceeds a preset value, that is, when a steering angle exceeds the preset value, the pressing body 10 rolls on the smooth circumferential surface of the rack 3. As a result, since the friction of the pressing body 10 against the movement of the rack 3 does not increase any more, the operation force of a steering wheel is not increased. Besides, since the component force of the spring is used as self-aligning torque, the return of the steering wheel to the neutral status is ensured.