To easily and surely fix an air pump on a ceiling panel by integrally fixing a frame through metal fixtures to the vibration-proofing members of rear side corner parts on a ceiling panel unit and fixing the air pump to the frame.

A ceiling panel 5 for a bathroom unit is constituted by linking two ceiling panel units 5A, vibration-proofing members 6 are spread over the rear side corner parts of one ceiling panel unit 5A and a frame 7 integrally screwing the leg parts of an air pump 8 is fixed to the vibration-proofing members 6. The frame 7 forms a wall-shaped flange 71 around it, and corner parts are arranged while being matched with the corner parts of the ceiling panel unit 5A. Then, the flange 71 of the frame 7 is integrally linked through a metal fixture K1 for fixing an inverse recessed terminal edge 51a of the ceiling panel unit 5A and a U-shaped upper terminal edge 41 of a wall panel 4, and the other flange 71 of the frame 7 is integrally linked through a metal fixture K2 for fixing the S-shaped terminal edge of the ceiling panel unit 5A and the inverse recessed terminal edge.