To provide a steering device provided with a steering lock device, wherein the stress that acts on the base of the flange section to which the steering lock device is attached is dampened.

Rounded corner sections 471, 481 are formed in recesses 47, 48 at the connection area between the recesses 47, 48 and the outer surface of an outer column 4. Because the recesses 47, 48 are formed so as to be recessed to a level below an attachment surface 445 by β3, the radius R1 of the rounded corner sections 471, 481 of the recesses 47, 48 can be formed to be larger than the radius R2 of a rounded corner section 447 of the attachment surface 445. Consequently, interference with a corner portion 631 at the inner end in the vehicle width direction of a clamping surface 63 of a steering lock device 6 can be avoided.