PURPOSE: To perform the common use of even roofs of different types by rotatably mounting two coupling parts by means of which a plurality of roof truss members are secured and providing a securing means to secure the coupling part at the given angle of a steel frame roof.

CONSTITUTION: A coupling metal 13 is formed with coupling parts 14A and 14B and securing parts 15A and 15B, and formed such that the two securing parts 15A and 15B are partially overlapped with each other. A plurality of hole parts 16 are formed in the coupling part 14A and hole parts 18A and 18B in the securing part 15A. A plurality of hole parts 19 are formed in the other coupling part 14B and, hole parts 20A, 20B, and 10C in the securing part 15B. The coupling parts 14A and 14B are brought into contact with respective inclination beams 11 and ridge beams 12, the hole parts 18B and 20B are secured by means of a bolt 17B and a nut 21, and the beams 11 and the ridge beams 12 are mounted to the coupling parts 14A and 14B by fastening a nut 17C against a bolt 17. This constitution performs the common use of the coupling metal 13.