FULL-FLAT REAR SEAT

A full-flat rear seat is a collapsible full-flat rear seat including a seatback board mounted on a rear surface of a backrest of the rear seat of a vehicle and providing a flat support surface together with a luggage board of the vehicle in being selectively unfolded, when the rear seat rotates, and the seatback board includes: a center seatback board mounted on a rear surface of the rear seat of the vehicle; an upper seatback board provided at an upper side of the center seatback board and configured to move relative to the center seatback board; and a lower seatback board provided at a lower side of the center seatback board and hinged thereto and configured to hingedly rotate toward one surface of the center seatback board.