An apparatus for processing material such as organically coated waste and organic materials including biomass, industrial waste, municipal solid waste and sludge, is provided. The apparatus comprises a rotatable and tiltable furnace (1) having a body portion (15), a single material entry point (11) and a tapered portion (13) between the entry point and the body. The furnace has a closure through which material can be introduced to the furnace (1) when open and in which the interior of the furnace is isolated from the external environment when closed. A director at or adjacent the entry point (11) directs gases inwardly of the furnace so as to provide a barrier of gas adjacent the opening to inhibit the entrance of oxygen containing atmospheric gas when the closure is in its open position.