Abstract: The fermentation plant for the biological degradation of organic material and for the collection of the bio gas formed during degradation has a closed container with a filling opening for fresh material and inoculated material and discharge openings for the degradation products as well as a stirring device for mixing the fermentation material. The stirring device has circularly moving stirring blades which are preferably individually driven in the container. Scrapers are provided on the container floor with which heavy precipitates deposited on the container floor are transported in batches to a discharge device. A flow system for a heating medium is also provided on the side walls which is optionally divided into several heating circuits to vary the temperature at various sectors of the heating surface.