A steering intermediate shaft has an inner shaft member and an outer tube member so engaged with each other as to be capable of transmitting rotation and to be slidable in an axial direction. The outer tube member includes slits so formed at one end as to extend in the axial direction. An annular fastening member is provided at a portion of the outer tube member formed with the slits to exert a fastening action inwards in a radial direction. The fastening member includes a disengagement preventing member for preventing the outer tube member from disengaging from the inner shaft member against an axial force within a predetermined value by engaging with the inner shaft member.