NOVELTY - The method for increasing biogas yield of a biodegradable substrate with a hydrolysis stage (2) and a thermal disintegration stage (4), which is carried out between the hydrolysis stage and a methane stage (5), comprises preventing the formation of the methane gas in the hydrolysis stage by adjusting the individual parameter. The hydrolysis stage is carried out at 38 degrees C with a pH-value of 5.5-6.5. Fructooligosaccharides (FOS)/toxic air contaminant (TAC) factor in the hydrolysis stage is 2-3. The retention time of the substrate in the hydrolysis stage is 5 hours to ten days.    USE - Method for increasing biogas yield of a biodegradable substrate with a hydrolysis stage and a thermal disintegration stage.    ADVANTAGE - The method is capable of economically and rapidly increasing the biogas yield of the biodegradable substrate with high efficiency in an improved manner, and reduces overall balance of the carbon dioxide.    DETAILED DESCRIPTION - The method for increasing biogas yield of a biodegradable substrate with a hydrolysis stage (2) and a thermal disintegration stage (4), which is performed between the hydrolysis stage and a methane stage (5), comprises preventing the formation of the methane gas in the hydrolysis stage by adjusting the individual parameter. The hydrolysis stage is carried out at 38 degrees C with a pH-value of 5.5-6.5. Fructooligosaccharides (FOS)/toxic air contaminant (TAC) factor in the hydrolysis stage is 2-3. The retention time of the substrate in the hydrolysis stage is 5 hours to ten days. The initial substrate in the hydrolysis stage has a trypsin-sensitive (TS) portion of greater than 30%. The thermal disintegration stage is operated at 70 degrees C with a pH value of 5.5-7. The retention time of the substrate in the thermal disintegration stage is 1-2 hours. The FOS/TAC factor in the thermal disintegration stage is 1.5-2.5. The methane stage is carried out at 50-55 degrees C with a pH-value of 7.5-8.0. The FOS/TAC factor in the methane stage is 0.3. The retention time of the substrate in the methane stage is 20-35 days. The concentration of the FOS factor is initially 15000 mg/l to finally 5000 mg/l, and the concentration of the TAC factor is initially 5000 to finally 15000 mg/l. An INDEPENDENT CLAIM is included for a plant for increasing biogas yield of a biodegradable substrate with a hydrolysis stage, a thermal disintegration stage and an anaerobic methane stage.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic block diagram of a plant.    Plant (1)    Hydrolysis stage (2)    Supply line (3)    Thermal disintegration stage (4)    Methane stage. (5)