PURPOSE: To ensure a large opening part between columns and firmly support a hanging wall to a lattice girder.

CONSTITUTION: A channel bracket 9 for nipping both lower surfaces 10a, 10b of a lattice girder 10 from under is mounted on the upper end part 4a of a hanging wall 4. A plate hanging wall reinforcing metal fitting 22 is arranged on the lower surface side of the channel bracket 9. The hanging wall reinforcing metal fitting 22 is connected to the latticed girder 10 in a position separated from the channel bracket 9 by a fixture 23 through a spacer 25. The channel bracket 9 nipping both the lower surfaces 1Oa, 1Ob of the lattice girder 10 is laid in the form supported from under by the hanging wall reinforcing metal fitting 22. The hanging wall 4 integrated with the hanging wall reinforcing metal fitting 22 can be firmly supported to the lattice girder 10. The opening width D between columns 1, 2 is never narrowed by the hanging wall 4.