TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Method: The methane reactor and the reactor or reactors for the hydrolysis are filled with support bodies on which microorganisms are immobilized necessary for the corresponding step, where the support body for the methane stage is made of foam cubes having an edge length of 10-30 mm, preferably 20 mm, or foam balls having a diameter of 10-30 mm, and the support body for the hydrolysis step is balls, Pall- or Raschig rings etc made of clay, ceramic or other materials. The content of the methane reactor and the hydrolysis reactor is mechanically stirred for homogenizing the contents, and/or is circulated via an external circuit (5), where the tempering of the circulation is carried by heat exchanger arranged in the external circuit. The filling levels of hydrolysis reactor and the fermenter (4) are controlled by overflow. The introduction of the substrate into the hydrolysis reactor and the introduction of the hydrolyzate into dip tube is formed curved at the end in an upward manner.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The nutrients, trace elements and vitamins (3) are supplied to the biogas process, which are not present in sufficient quantity in the substrate. A digestate from biogas plant free of solid materials is used for supplying with liquid nutrients, trace elements and liquid vitamins, whose substrate is vegetable and/or animal origin. The process is disconnected in an aerobic hydrolysis- and a methane step, and is carried out in two separate reactor steps, where the conditions for the microorganisms in each step are designed optimally such that hydrolyzate resulting in the hydrolysis step has mainly of lower organic acids. The hydrolyzate is supplied to methane reactor and is converted to biogas with a methane content of at least 60%. The substrate addition is carried out continuously or quasi-continuously, and the hydrolysis step of at least one reactor is associated parallely with the methane reactor that is actively aerated. EXAMPLE - No suitable example given.