To fix a column to a beam by forming a connecting hardware having a back plate and side pieces formed thereon, forming a pipe having a nut screw on the inside of one end part thereof, and screwing a bolt inserted to the pipe inserted to the pipe hole of the back plate bay a nut.

A connecting hardware 11 has notches 12 formed on both side pieces 21 and corresponding through-holes 13 arranged on both the side pieces 21. Projections 19 protruded on the end part of a metal beam 2 are fitted to the notches 12 to put one end of the metal beam 2 between both the side pieces 21, and a bolt 25 is inserted to trough-holes 24 on the end part of the metal beam 2 through the through-holes 13. Then, a nut 27 is fastened to connect the metal beam 2 to the side pieces 31 of the connecting hardware 11. The metal beam 2 is temporarily fixed to the connecting hardware 11 by fitting the projections 19 protruded on the end part to the notches 12. Thus, the following work of inserting the bolt 25 to the through-holes 24 on the end part of the metal beam 2 through the trough-holes 13 of both the side pieces 21 to finish the fastening can be facilitated to improve the working property.