NOVELTY - The production of biogas from a cellulose substrate (9) comprises feeding a substrate and a liquid to a reactor unit containing microorganisms, splitting the substrate during a hydrolysis to from intermediate product, dismantling the intermediate product to short-chain fatty acids and dismantling the fatty acids to biogas. The liquid containing microorganisms is filled in a first reactor and in a second reactor connected with the first reactor via pipeline (6). The cellulose substrate and aqueous solution containing electrolytes are fed into the first reactor.    USE - For the production of biogas from waste paper, paperboard, leaves, plant stacks, stem products, grass, straw and residues from the paper and pulp industry, the pharmaceutical industry or the chemical industry.    ADVANTAGE - The ecologically harmless cellulose substrates like waste paper, paperboard, leaves, plant stalks, stalk crops, grass and straw are easily available in everywhere so that the procedure ensures easy and high production of biogas in cost effective manner.    DETAILED DESCRIPTION - The production of biogas from a cellulose substrate (9) comprises feeding a substrate and a liquid to a reactor unit containing microorganisms, splitting the substrate during a hydrolysis to from intermediate product, dismantling the intermediate product to short-chain fatty acids and dismantling the fatty acids to biogas. The liquid containing microorganisms is filled in a first reactor and in a second reactor connected with the first reactor via pipeline (6). The cellulose substrate and aqueous solution containing electrolytes are fed into the first reactor. The reactors together form the reactor unit. The contents of the first reactor are held permanently in a temperature of 35-41 degreesC. The aqueous solution containing the fatty acids is removed from the first reactor working under anaerobic conditions and is supplied to the second reactor working under anaerobic conditions in which the fat acids are dismantled to biogas. The biogas is obtained from the both reactors, is collected at the bottom of the first reactor and is drained from the cellulose substrate. The cellulose substrate with aqueous solution is supplied to a preheating mechanism, which is connected to the first reactor. The mixture from the cellulose substrate and aqueous solution is pumped upwardly within the interior container in a time intervals. The aqueous solution in the second reactor is moved by an agitator. An INDEPENDENT CLAIM is included for a device for the production of biogas from a cellulose substrate.    DESCRIPTION OF DRAWING(S) - The diagram shows a device for the production of biogas from a cellulose substrate:    Container; (1)    Feed pump; (4)    Circulating pump; (5)    Pipeline; (6)    Cellulose substrate. (9)