An apparatus for receiving and processing organic waste by anaerobic bioconversion comprising a closed tank which is the bioconversion site, provided in the top portion thereof with a gasometric bell for storing and pressurizing the biogas produced, around which the external members of the apparatus are distributed on a pod which also forms the support for a body of the digester. The tank, in a preferred embodiment, comprises a main enclosure which is the bioconversion site, and a secondary central enclosure called the crop, intended to receive and store the organic waste to be processed before the dosing of same into the main enclosure to complete the bioconversion. The crop forms a removable subassembly that can be configured in different ways, with a circulation and distribution block on which it is secured and with a liquid-solid phase separator which is mounted over same. This subassembly engages with a mechanical stirrer for stirring the fermentative medium contained inside the tank, driven by the gasometric bell, which is centered and rotated by a drive device, for example one carried by the arm of a telescopic bracket mounted over same, or by a drive ring.