To damp vibration or the like from a wheel to prevent transmission of the vibration or the like to a steering wheel, inhibit striking sounds at the meshing parts of the gears of a speed reducer and at ball screws, and provide a collapse mechanism for a vehicle collision, etc.

A steering shaft 10 is divided into a first shaft 11 for connection to the steering wheel and a second shaft 12 for connection to the underside of the first shaft 11, with the first and second shafts freely slidably fitted one into the other. A shock-absorbing member 17 is interposed between the first shaft 11 and the second shaft 12. When a collapsing load acts on the steering shaft 10, the shock-absorbing member 17 permits sliding of the first shaft 11 so that the first shaft 11 collapses and contracts.