PURPOSE: To achieve the simplification of the housing and arranging of a bath lid while enabling the utilization of the bath lid as stool by a method wherein a shorter side part of the bath tub is arranged adjoining on an outlet/inlet opening to a bath room and the bath lid is pivoted on the shorter side part of the bath tub free to turn.

CONSTITUTION: One shorter side part 5 of a bath tub 4 is arranged adjoining on an outlet/inlet opening 7 to a bath room. A first bath lid 8 and a second bath lid 9 are mounted with respective hinges on the other shorter side part 6 on the side opposite to the outlet/inlet opening 7 to the bath room. A pin 27 with which a rail groove 22 is guided is erected on the other end side of a connection member 23 and the first bath lid 8 is mounted between arms 20 for receiving the bath lid as opposed to each other through the connection member 23. After use thereof as connection plate to a bench 12, the first bath lid 8 is housed almost vertically on the side of the bath tub 4 while a user is taking bath. Thus, the second bath lid 9 is turned or slid to be set across the other end side part 6 of the bath tub and the bath lid receiving part 30 thereby enabling the utilization thereof as stool.