To provide a heating apparatus to carbonize even chaff with a low ignition temperature without ignition and a preparation method of chaff carbon such as rice chaff using the heating apparatus.

A heater 1 is shaped into a box and plural infrared ray radiation sources 2 are disposed inside the heater. A heat radiation surface 11 is provided on the lower surface of the heater 1 and a heat insulation surface 12 is provided on the upper surface of the heater 1. The heat radiation surface 11 comprises a metal plate 11a and black body coating surfaces 11b with a thickness of about 2 mm on the both sides of the metal plate. The heat insulation surface 12 comprises a metal plate 12a and a heat insulation material 12b.