A structure capable of preventing improper wheel alignment even when, for example, an accident such as a collision accident, steered wheels riding on a curb, or the like occurs is realized. A telescopic shaft in which the inner shaft (9a) and the outer tube (10a) are combined with each other by a spline engagement between the male spline portion (45) provided on one end portion in the axial direction of the outer-circumferential surface of the inner shaft (9a) and the female spline portion (23) provided on the other end portion of the inner-circumferential surface of the outer tube (10a) such that torque can be transmitted and the entire length of the telescopic shaft can be extended and contracted, the inner shaft (9a) having an inner-side small-diameter cylindrical portion (41) provided on a portion of the inner shaft (9a) that is located further on the other side than the edge of the other end in the axial direction of the outer tube (10a) and having an outer-diameter dimension that is smaller than the adjacent portions on both sides in the axial direction thereof, is provided.