To reduce stepped difference between a bottom plate surface and a floor face in a fitting room.

In the plane square-shaped fitting room in which the three sides are formed in wallboards in fixed height and a curtain 13 is hung down from one entrance in a freely openable-closeable manner, auxiliary wallboards 2, 2a are installed at the left-right edges of a rear wallboard 1 respectively while left-right side wallboards 3, 3a are hinged to the auxiliary wallboards 2, 2a respectively, the rear edge of a bottom board 11 is hinged rotatably to the lower section of the rear wallboard 1, and the front edge of the bottom board 11 is thinned and stepped difference is reduced and the fitting room for the aged or the like is formed.