To materialize a structure capable of stably holding an inner colum on an inner diameter side of an outer colum.

An outer colum 13d and a moving side bracket 22b are integrally bulge-molded by a hydroform method and the like. Bulging portions 23a and 23a configuring a supporting portion 26 of the outer colum 13d, and an outer peripheral surface of an inner colum 14c are made to abut on each other only at three parts in a circumferential direction. On width direction outside surfaces of clipped plate portions 25a and 25a of the moving side bracket 22b, around an axial direction intermediate portion of a colum side through-hole 30, a projecting portion 31 is provided so as to project out from both width direction outside surfaces in a width direction. While being assembled, width direction inside surfaces of supporting plate portions 28 and 28 of a fixed side bracket 12b are made to abut on the width direction outside surface of the projecting portion 31.