To shorten a construction period by means of attaching fire extinguishing equipment immediately after assembling a light ceiling by constituting the equipment in such a way that metallic hanging fixtures are fixed to a fixing member which is fixed to a slab and a flexible tube which is connected to a water supply main pipe fixed to the slab is hung.

An elbow 7 to which a sprinkler head 8 is previously connected is connected to the tip of the flexible tube 6a. Then, the metallic hanging fixtures 9 and 19 are fixed to the fixing member 14 which is buried in the slab 1 and a branch pipe 2 is hung from the hanging fixtures 9. A header 4a is attached to the branch pipe 2 and the flexible tube 6a is connected to the connection port 5c. The connecting part of the elbow 7 is hung from the slab 1 by the fixtures 19. Thus, the construction of the branch pipe 2 and the flexible tube 6 is executed before assembling the light ceiling material 10 and easily executed.