NOVELTY - The filth or waste (13) treating process comprises subjecting filth or waste to compression to separate (14) into a putrescible fraction in the form of pulp (15) having relative humidity of greater than 50% and into a dry fraction having relative humidity of less than 20%, and subjecting the putrescible fraction to an anaerobic digestion to produce biogas. A part of the dry fraction is converted by an endothermic gasification treatment to produce synthesis gas. The synthesis gas comprises a fuel gas able to be burned by exothermic oxidation.    USE - The process is useful for treating filth or waste such as domestic wastes including garbage waste, agricultural waste including manure and plants and food wastes.    ADVANTAGE - The process ensures economical, easy and energy efficient treatment of filth or waste, and ensures complete and safe recovery of wastes without any emission of hazardous gas thus avoiding the environmental pollution during the treatment.    DETAILED DESCRIPTION - The filth or waste (13) treating process comprises subjecting filth or waste to compression to separate (14) into a putrescible fraction in the form of pulp (15) having relative humidity of greater than 50% and into a dry fraction having relative humidity of less than 20%, and subjecting the putrescible fraction to an anaerobic digestion to produce biogas. A part of the dry fraction is converted by an endothermic gasification treatment to produce synthesis gas. The synthesis gas comprises a fuel gas able to be burned by exothermic oxidation. The endothermic gasification treatment is carried out in a gasification reactor at 700-900 degrees C using many reagents comprising a part of dry fraction (10%) and water vapor. The heat energy for the endothermic gasification treatment is provided outside the reactor by a combustion of biogas and the dry fraction with a quantity of oxidizing comburant gas (6000 m3 per tonne) in the gasification reactor. The comburant gas is heated by heat exchange between a portion of synthesis gas produced by the endothermic gasification treatment and the comburant gas. The separation into the putrescible fraction and the dry fraction is carried out at a pressure of 720-750 bars in a compression chamber having extrusion orifices through which the putrescible fraction flows. A gas composition including recycling gas is prepared and stored in the reactor. The gas includes a quantity of synthesis gas and a quantity of biogas and natural gas.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic flowchart of a filth or waste treating process.    Initial composition (10)    Extracting the inert material (11)    Inert material (12)    Filth and waste (13)    Separating the filth and waste (14)    Pulp. (15)