PURPOSE: To provide such an adjusting stopper as improving its working property whenever a tilt lever of a tilt steering column is adjusted to the specified position.

CONSTITUTION: This is one that pertains to an adjusting stopper where clamping bolt 8 is pierced through a long hole installed in both side walls of a fixed bracket in a tilt steering column, and engaging with a peripheral tooth part 9 formed in a flange part 8c of this clamping bolt 8 for whirl-stopping, and being slidable. This adjusting stopper 11 is composed of a sliding guide part 12 installing a curved surface 18 being fitted in the long hole and coming into contact with a shank part of this clamping bolt 8, and a frame body being integrally formed with this sliding guide part 12, surrounding the flange part 8c of the bolt 8, having at least elastic or flexible two side parts (flexible part) 19 and 19 being opposed to each other, and forming each circular inner circumferential tooth part 21 in the inner circumferential surface of other two side parts, respectively.