To solve the problem that the conventional height adjusting device is liable to produce displacement of a center axis of a bolt to a center axis of a bolt insertion hole and is liable to produce inclination of the bolt.

The bolt insertion hole 3 inserting the adjusting bolt 4 is vertically penetrated at a prescribed position of a concrete member 2 laid on the upper face of a foundation concrete 1, and a step-like large diameter part 8 is formed on the lower part of the bolt insertion hole 3. An inside diameter of an upper end 6b of an upper end side small diameter part 6 of the bolt insertion hole 3 is set slightly larger than an outside diameter of the adjusting bolt 4, and an inside diameter of the upper end of the large diameter part 8 is set slightly smaller than an outside diameter of a nut part 11 of an adjusting fitting 5. The center axes of the adjusting bolt 4 and the bolt insertion hole 3 are positioned by the inner peripheral face of each upper end of the small diameter part and the large diameter part.