To provide a steering device which can firmly support a cylindrical housing supporting a rack shaft on an additionally attached mount member of easily being fixed, and can reduce a machining and assembling man-hours without requiring an additional machining after being fixed.

In the steering device, a cylindrical rack housing 10 which movably supports the rack shaft 1 in the axial length direction and has a cylinder chamber 52 of a power cylinder 5 for a steering auxiliary in the interior is mounted to a part of the vehicle through a mounting member 2 provided in the vicinity of opening end part of one side of this. The mounting member 2 is constituted so as to be fixed by press fitting of a fixing ring 20 to the outside of the rack housing 10.