To suppress the vibration of a ceiling material by hoisting and supporting a ceiling panel for a floor beam which supports a floor material through a ceiling vibrationproof elastic member consisting of a pair of support plates and vibrationproof rubber.

A floor material 1 is fixed on a floor beam 3 through a floor joist 2, and a ceiling material 4 constituted by a plurality of ceiling panels 41 for the floor beam 3 is hoisted and supported through a ceiling vibrationproof elastic member 5. The ceiling vibrationproof elastic member 5 is formed by a pair of support plates 51, 52 which are provided in parallel and a vibrationproof rubber 53 provided between the support plates 51 and 52. Furthermore, an elastic caulking material 6 as a vibrationproof elastic member between panels is provided over the whole length between the ceiling panels 41 and 41. Consequently, it is possible to suppress the vibration of the ceiling material 4 doubly by the ceiling vibrationproof elastic member 5 and the elastic caulking material 6 so that high sound isolation effect is obtained.