PURPOSE: To enable the total beds of airplane, bus or the like to perform full reclining without decreasing the number of seats, by making the lower floor of a seat lower than the passage and setting the front and rear arrangement of the seats in lowered and raised positions alternately.

CONSTITUTION: Lower floor 5 of a seat is further lowered by one step from passage 4 and ceiling is made higher than usual. Front and rear seats are arranged in such a way that steps are provided on every other line and a passenger is supposed to make a step upward or downward in order to sit on a lower or upper seat respectively. However, the lower seat is provided with a reciprocal sliding apparatus 12 at lowered flower 5 so as to fix seat thereupon. The foot area of the lowered seat is so wide that the sliding apparatus can be operated to slide forward and the seat back 2 is lay in horizontally position to be full reclining. The upper seat is located above column 7 to be full reclining in its position.