To securely support a rafter for a sheath pipe horizontally between two column material by a simple work.

This device is provided with an installation piece 11 having an installation hole to be installed on a column material, a receiving piece 12 perpendicularly protruded from one side of the installation piece 11, and two arm pieces 13 protruded from two sides perpendicular to the side of the installation piece 11 respectively in the same direction as the receiving piece 12. To a wall surface of the column material, this is fixed to the wall surface by a machine screw at the installation hole in the installation piece 11, and to an opening surface of the column material having folded edge parts 25, it is fixed by a bolt inserted through the installation hole in the installation piece 11, with a plate nut threaded with the tip side of the bolt and tightened to the folded edge parts 25 from the inner side.