To increase a workability when fixing a hanger for supporting an article to a floor plate laid out in a ceiling space.

The floor plates 1 laid out in the ceiling space of a house are connected to each other in the state of forming vertically passing clearances 4 between the side faces thereof adjacent. to each other. The hanger 7 can be vertically inserted through the clearance in the floor plate 1 and comprises a vertical part 8 longitudinally formed from the floor plate 1 and a support part 10 formed wider than the clearance 4 in the floor plate 1. The vertical part 8 is inserted into the clearance 4 from the upper part of the floor plate 1, and the support part 10 is supported between both floor plates 1. Thus the vertical part 8 can be exposed from the floor plates 1 to a lower side and a support member 11 for supporting the article can be fixed to the vertical part 8 exposed from the floor plate 1.