A sample heating device includes: a rail-shaped disposal rail extending in one direction in a horizontal plane so that sample boats after heating are arranged and placed in a straight line; a disposal tray that houses the sample boat pushed-out from one end of the disposal rail; a sample boat conveying portion that places the sample boat after the heating at a predetermined placing position on the disposal rail; and a sample boat push-out portion that is positioned closer to the other end side of the disposal rail than the placing position when the sample boat is placed on the disposal rail and that is displaced toward the one end side of the disposal rail after the sample boat is placed at the placing position to slide the sample boats on the disposal rail toward the one end side.