To house an installation apparatus in the state having no clearance with a wall in setting the apparatus such as dressing washstand along the wall by providing a filler on the side part laid along the wall of the apparatus, and shielding the clearance between the apparatus and the wall by use of the filler.

Fillers 11 and 12 are provided in the whole range extending from the floor surface to the ceiling surface of the side part laid along the inner wall panels 4 and 5 of the counter 10A of a dressing washstand 10. Namely, the clearance between the dressing washstand 10 and the inner wall panels 4 and 5 is shielded by the fillers 11 and 12 provided on the side part of the dressing washstand 10, whereby the dressing washstand 10 can be consequently housed in the state having no clearance with the inner wall panels 4, 5. Therefore, the clearance between the dressing washstand 10 and the inner wall panels 4 and 5 resulted from the horizontal or vertical distortion of the inner panels 4 and 5 along which the dressing washstand 10 is set can be shielded to improve the apparent design property of fitting of the dressing washstand 10, and the falling of dust or water to between the dressing washstand 10 and the inner wall panels 4 and 5 can be prevented to improve the cleanliness around the dressing washstand 10.