NOVELTY - A plant for the biological stabilization of fermentable waste, has a program installed in a computerized control unit to automatically control an air flow rate regulator and control the fermentation temperature in each sector accordingly, to accelerate fermentation of the waste on the basis of its composition, nature and degree of fermentation.    USE - The plant is useful for the biological stabilization of fermentable waste, especially organic and wet fractions of solid waste such as municipal solid waste, containing moisture of under 16 wt.%, net heat of over 17000 kJ/kg (4000 kcal/kg), and a bacteria count of under 105 N/g (claimed).    ADVANTAGE - The inventive plant can optimize the production of stabilized, dry refused derived fuel (RDF) with a high net heat value. It can also produce RDF which takes account of variations in the composition and reactivity of the waste to be stabilized. It is fully-automated and simple and cheap to run. It can also produce sanitized RDF, with a low bacteria count and no pathogenic germs. It can also produce stabilized RDF fuel which is practically odorless and non-fermentable, even in the presence of external humidity.    DETAILED DESCRIPTION - A plant for the biological stabilization of fermentable waste, comprises:    (a) a fermentation chamber (3) which is closed, with pre-determined dimensions;    (b) a support surface (16) divided into sectors that is located in the chamber for stratified deposit of waste (W), which the support surface contains openings distributed uniformly in the sectors for the passage of air;    (c) a crusher (5) for coarse crushing of waste;    (d) mechanisms (7-9) for deposit of crushed waste on the support surface in each sector and for the transfer of waste between the various sectors and between the various areas of the plant;    (e) fans (13) for aspirating air from above and conveying it through the openings in the support surface so that the air passes through the stratified waste on the surface and promotes its forced fermentation;    (f) regulators for regulation of the flow rate of the air aspirated in each sector.    A first sensor is provided for detection of the temperature of the air aspirated upstream and downstream of the stratified waste in each sector. A second sensor detects the humidity of the air aspirated upstream and downstream of the stratified waste in each sector. A third sensor detects the air flow rate downstream of the waste in each sector. A computerized control unit is designed to process the signals originating from the thee sensors and to the air flow regulator in each sector. A program is installed in the computerized control unit to automatically control the air flow rate regulator and control the fermentation temperature (T) in each sector accordingly, to accelerate fermentation of the waste on the basis of its composition, nature and degree of fermentation.    INDEPENDENT CLAIMS are also included for:    (1) waste stabilization method;    (2) computer program designed to activate and control a waste stabilization plant; and    (3) stabilized waste.    DESCRIPTION OF DRAWING(S) - The figure is a diagram of the waste stabilization plant of the invention.    Fermentation chamber (3)    Crusher (5)    Depositing mechanisms (7-9)    Fans (13)    Manifold (14)    Support surface (16)    Fixed support (17)    Suction cells (18)    Fermentation temperature (T)    Waste (W)