In a steering device having a steering lock device, the stress applied to around a through hole formed in a column to which the steering block device is attached is reduced. Since there is a slight clearance formed, in the vehicle height direction, between the outer periphery of the lock pin and the through hole and also between the guide groove and the engaging convex part, the clamping force is born by the flange section and first ribs and also by the flange section and second ribs without any force applied to the through hole. The engaging convex part is not fitted in the through hole, so that the through hole is only required to be large enough to allow the lock pin whose cross-sectional area is smaller than that of the engaging convex part to come in and out. This makes it possible to reduce the cross-sectional area of the through hole and thereby increase the strength of the outer column.