When a column 4 reaches a tilting ascent end, the lower end 732 of a nut 73 abuts on the buffering segment 83 of a buffer 82. Thus, while the buffering segment 83 of the buffer 82 is elastically deformed, the nut 73 stops with no impact. Accordingly, the inertia when the nut 73 stops is restrained and the tightening torque of the nut 73 when the nut 73 stops is also restrained. For this reason, when an electric motor 61 is rotationally driven in a reverse direction, a feeding screw shaft 71 rotates in the reverse direction with the normal rotation torque of the electric motor 61. Thus, the nut 73 is caused to ascend in the axial direction along the screw segment of the feeding screw shaft 71 so that the column 4 can be tiltingly moved downward.