PURPOSE: To easily fix a truss to a roof structure, by supporting both ends of the truss by support metal tools installed in the roof structure so that the lower face of the truss arranged at the upper part of the roof beam is separated from the upper face of the roof beam.

CONSTITUTION: Truss-support pieces 9 are connected and fixed to both ends of a truss 3 and the connection piece 15 of the truss-support pieces 9 is connected and fixed to a horizontally extending piece 10 with a fixing tool 13. In this case, the truss 3 is installed above a roof beam 1 so that the truss is separated from the upper face of the roof beam 1 by this connection. A roof panel is installed above the truss 3 and frame materials of the roof panel are placed on the upper face of an inclined piece 6. The inclined piece 6 and the frame material are connected and fixed mutually with the fixing tool 13 and supported by the support metal tool 4.