NOVELTY - The method and device for the production of biogas from biomass in a biogas fermenter (11), comprise dynamically mixing the biomass and then degassing the biogas from the biomass by injecting the biogas or a mixture of biogas and digestate at the bottom of the fermenter having sequentially arranged three chambers (7, 6, 12), basins and gas spaces (4, 10) that are arranged through two partially closed and vertical separating walls (5, 13).    USE - Procedure and device for the production of biogas from biomass in a biogas fermenter (claimed).    ADVANTAGE - The method and device ensure economical and flexible production of biogas from biomass with high throughput, less energy consumption and high controllability without any mechanical agitators for adjusting the fermentation of energy crops, in faster and efficient manner.    DETAILED DESCRIPTION - The method and device for the production of biogas from biomass in a biogas fermenter (11), comprise dynamically mixing the biomass and then degassing the biogas from the biomass by injecting the biogas or a mixture of biogas and digestate at the bottom of the fermenter having sequentially arranged three chambers (7, 6, 12), basins and gas spaces (4, 10) that are arranged through two partially closed and vertical separating walls (5, 13). Through the separating walls, a gas-tight separating wall separates the gas space of the first chamber by the fermenter cover downwards from the gas space of the adjacent chamber and extends up to a determined depth in the biomass level (19), and through which a liquid-tight separating wall separates the biomass of the last chamber from fermenter bottom upwards up to a determined height of the biomass of the further chamber. The entry of the biomass into the fermenter in the first chamber in the upper range and the discharge of the biomass from the fermenter into the later chamber in the lower range are carried out by the liquid-tight separating wall so that a down flow of the biomass takes place in the first chamber, an up-flow of the biomass takes place in the subsequent chamber, the further successions of down flow and up flow caused by alternative arrangement of separating walls takes place during discharge at a point in the lower level of the last chamber, which is again operated in the up flow. The fermenter bottom causes different additional gas pressures in the gas spaces over the biomass by closing and opening of gas exhaust valves. The different biomass levels are caused within the individual fermenter chambers. The regulation of the gas pressure in the respective gas space takes place by the quantity of the biogas injection at the fermenter bottom of the respective chamber and over opening or closing of a regulating valve in the gas outlet piping of the gas chamber and by a regulating valve to the confluence of the gas flows. The negative pressure is produced in the biomass of the various chambers, in which different biomass levels in the chambers are produced by increasing the gas pressure in the respective chamber in hydrostatical manner. The gas exhaust valves of the chamber are closed with the higher biomass level. A screen is attached in the last chamber for the separation of the fermented biomass in a liquid fraction and a fraction with higher contents of fibrous materials. The cleaning and opening of clogged holes of the screen take place by nozzles of biogas within the bottom area of the fermenter. A hydrostatic connection between the last chamber and the first chamber is installed by pipe and regulating valve. A pumping of biomass from the lower area of the last chamber to the upper area of the first chamber is carried out by the production of a pressure gradient by gas positive pressure in the gas space of the last chamber and simultaneously by hydrostatic pressure of the biomass for last chamber. The liquid-tight separating wall is formed for the separation of the biomass tubs, each of which has a small inclination of the fermenter bottom to an outlet and acts as outlets for the removal of stones. The flow of the biomass is supported by inlets, in which the biomass level of the last chamber is increased by gas positive pressure in the further gas space with opened gas exhaust valve over the last chamber and in this condition, the outlets are opened for delivering the fermented biomass from the fermenter and adjust a lower biomass level in the fermenter chamber after pressure balance in the both last gas spaces. A triangular conductive plate is installed with an angle of greater than 90 degrees to the horizontal biomass level at the gas-tight separating wall to cause the returning of the biomass from a chamber with up-flow characteristic into the subsequent chamber.    DESCRIPTION OF DRAWING(S) - The diagram shows a fermenter with three chambers.    Gas spaces (4, 10)    Separating walls (5, 13)    Chambers (7, 6, 12)    Fermenter (11)    Biomass level. (19)