Abstract: A composting apparatus having a heating unit is disclosed so that the heating unit is heated by the composting of material in the apparatus. The heating unit (200, 300) may be used to heat foodstuffs or other material such as soil for growing plants or additional compostable material. The heating unit (300) may have holes (307) for allowing air to enter the oven. The unit may also include a conduit which is wrapped around the heating unit for facilitating heating of the heating unit (300) and for also supplying heated fluid to drive a pump or turbine (460). A condensing chamber (430) is provided for allowing heated fluid to condense and a conduit (422) is provided for returning the condensed fluid to the storage chamber (403) within the composting material (C).