TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Process: The processed substances or the mixed substrate and the formed materials and the microorganisms are flowed through an area having the extended formation of the electric and magnetic fields in the process areas. The redox potential of the fermentation substrates in the first and second process area of the biogas reactor is optimized by the effect of constant or pulsed electric and magnetic fields in the anaerobic phase. The efficiency of the biogas reactor is increased by the hydrogen formed by an electrical voltage, which is induced according to the Hall-effect using the clustered arrangement of electrodes and magnets or magnetic core coil in a lift pump (55). The growth rate of microorganisms is increased in the biogas reactor by the treatment with constant or pulsed electric and magnetic fields, and the cell mortality is minimized. The mixing and circulation of the fermentation substrate in the process area of the first step and the process area of the second step of the biogas reactor, takes place with the help of the gas supply system and arranged lift pumps. The produced biogas of the first step is incorporated in the process area of the second step of the biogas reactor with the help of a compression of the gases via the gas supply system. The formation of hydrogen sulfide is prevented by the entry of air or oxygen via the gas supply system in the lift pumps of the first and second process area and by the effect of constant or pulsed electric and magnetic fields in the process area. The fermentation substrate from the process area of the second step is fed into the process area of the first step of the biogas reactor for setting an optimal pH in the process area of the first step. The pressure control between the gas area of the first step and the gas area of the second step of the biogas reactor takes place by a differential pressure control via an external control valve. The fermentation substrate flows in and flows out by vertical slits, which combine the first and the second process area of the biogas reactor. The processing of organic material takes place with the help of a mixing tool in a mixing vessel and by a screw assembly, which is arranged in the external circuit of the processing. The degraded fermentation substrate from the collecting tank is led back for processing the substances and is fed into a mixing container (44). The population of microorganisms in the first and second process area of the biogas reactor is concentrated by the reduction of the degraded fermentation substrate. In a mesophilic-thermophilic or thermophilic operation of the biogas reactor, process energy is obtained by the reduction of the degraded fermentation substrate and the feeding into the mixing container over a recuperative system.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: In a mesophilic operation of the biogas reactor, a heat exchanger (15) is arranged only in the second process area. In a thermophilic or mesophilic-thermophilic operation of the biogas reactor, a heat exchanger is arranged in the first process area and the second process area. In the core area of the first procedure step 3-5 lift pumps and in the annular space of the second step, 6-12 lift pumps are arranged in the biogas reactor. The modules with the clustered arrangement of electrodes and permanent magnets (63, 65) according to the figure 5 and figure 6 of the specification for the device according to figure 1 or figure 2 of the specification are arranged in the vertical axis of the lift pumps. The modules with the clustered arrangement of electrodes and magnetic core coils according to figure 7 and 8 of the specification for a device according to figure 1 or 2 of the specification are arranged in the vertical axis of the lift pumps. The electrodes of cylindrical rings or segments are arranged in a module of the gas supply system under a transparent tube according to figure 5 and 6 of the specification. The permanent magnets of cylindrical rings or segments are arranged in a module of the gas supply system with the north-south pole orientation under a transparent tube according to the figure 5 and 6 of the specification. The electrodes of cylindrical rings or segments are arranged in a module of the gas supply system under the transparent tube. The magnetic core coils made of cylindrical rings or core segments are arranged in a module of the gas supply system with the north-south pole orientation under the transparent tube. EXAMPLE - No suitable example given.