To provide a measure required for coping with the situations that installation of a chair seat becomes indispensable even in a ceremonial hall with tatami mats because persons feeling pain or difficulty in sitting on a tatami floor due to their aging or a change in a lifestyle increase among participants in a religious ceremony held in the main temple or the like who usually sit formally on the tatami floor, that a corner of the main temple becomes a place to store chairs as the result and the tatami mats are injured each time by the chair carried, arranged, used and restored by each person, and that such situations as the above, which impair the dignity of religious facilities in a large degree, are anticipated to increase more and more in the future.

The apparatus for automatic setting of a chair is installed in the hall with the tatami mats of a Buddhist temple or the like. A framework base whereon folding chairs are mounted is attached to floor framing under the tatami. The chairs are raised vertically onto a floor by a rotational motion by an electric device, opened manually to be used, and stored under the tatami after the use as they are before. As for the tatami mat on the framework base, a surface material equivalent to an existing one is used therefor while a substrate board is divided to be foldable and made to move in connection with the rise and fall of the chair.