Elongated holes are formed in a first plate of a fixed bracket so as to extend parallel to a column moving direction. An elongated hole inserted portion of a suspending bolt of a suspending mechanism is disposed in an initial assembling position in one of the elongated holes. An inner circumference of the elongated hole includes a pair of flat surface portions which are parallel to the column moving direction, an arc-shaped surface portion and tapered surface portions which connect a pair of end portions of the arc-shaped surface portion to the corresponding flat surface portion. Tapered angles which the tapered surfaces form relative to the column moving direction are equal to or greater than a friction angle.
