NOVELTY - The bioreactor for methanation of biomass with high solid content, comprises a gas-tightly lockable decomposition container (2), a biogas discharge line (18), a filling- and emptying opening (14) for filling and emptying the container with biomass, a percolating juice- and/or percolate-drainage device (22) arranged in the base and/or the walls of the container. The decomposition container is formed liquid tight. The percolate-drainage device is connected with a percolate-controlling device, to regulate the liquid level of the percolates in the container.    USE - For methanation of biomass with high solid content.    ADVANTAGE - The bioreactor increases the biogas yield and reduces the necessary residence time of the biomass in the container.    DETAILED DESCRIPTION - The bioreactor for methanation of biomass with high solid content, comprises a gas-tightly lockable decomposition container (2), a biogas discharge line (18), a filling- and emptying opening (14) for filling and emptying the container with biomass, a percolating juice- and/or percolate-drainage device (22) arranged in the base and/or the walls of the container. The decomposition container is formed liquid tight. The percolate-drainage device is connected with a percolate-controlling device, to regulate the liquid level of the percolates in the container. The percolate-controlling device comprises percolate-storage that is connected with the percolate-drainage device by a percolate-discharge line in which a valve is arranged. The percolate-controlling device comprises a percolate pump arranged in the percolate-discharge line. A pressure sensor is arranged in the percolate-discharge line or in the container for detecting the percolate-liquid level in the container. The controlling device comprises a percolate-return line, which connects the percolate-storage with the upper area of the container. The filling- and emptying opening is a hydraulically operatable flap, which locks the container at ground level. A restraining device is arranged behind the flap in filling direction in such a way that the filled biomass in the container supports partially at the restraining device. Packing is brought into the percolate storage, at which biogas can be accumulated to produce microorganism. The storage comprises a biogas extraction line. The packing is formed a packing bed from biomass with high solid content. An INDEPENDENT CLAIM is included for a biogas production device with multiple bioreactors.    DESCRIPTION OF DRAWING(S) - The drawing shows a bioreactor for methanation of biomass with high solid content:    Decomposition container; (2)    Base plate; (6)    Filling- and emptying opening; (14)    Biogas-discharge line; (18)    Percolating juice- and/or percolate-drainage device. (22)