To simplify works for forming a ceiling substrate and reduce the cost of the work by supporting a joist with a through hole formed in a cradling receiver fitted to the lower end of a hanging member and fixing both ends to a wall.

A cradling receiver 18 is fitted to the lower end of a hanging member 16 fixed to a hanging beam 12 at the upper end and both ends of the cradling 20 supported through the cradling receiver 18 are fixed to walls 10, 10. The cradling receiver 18 is made of steel and provided with a through hole 18d. The joist 20 is inserted in the through hole 18d to support it. The joist receiver 18 is constituted of a pair of parallel flanges 18a, 18b and a rib- shaped part 18c connecting these flanges. A through hole 18d is formed in the rib-shaped part 18c and the lower end thereof is partitioned by the lower flange 18b. In this way, the construction work of the ceiling substrate can be simplified and the construction cost can be reduced.