NOVELTY - The device comprises fermenters (13), and a percolate tank (10) for collecting the percolate removed from the fermenters, where the percolate tank has a percolate inlet (10c) that is connected to an outlet of the fermenters, and a percolate outlet (10b). The percolate tank is designed in such a way that the residence time of the percolate at its path between the inlet and the outlet is long to sanitize the percolate at the outlet. The percolate tank has meander-shaped flow path between the inlet and the outlet, and is arranged below the fermenters.    USE - Device for recovering biogas.    ADVANTAGE - The device is capable of effectively and simply recovering the biogas without unwanted germs, bacteria or other contaminants.    DETAILED DESCRIPTION - The device comprises fermenters (13), and a percolate tank (10) for collecting the percolate removed from the fermenters, where the percolate tank has a percolate inlet (10c) that is connected to an outlet of the fermenters, and a percolate outlet (10b). The percolate tank is designed in such a way that the residence time of the percolate at its path between the inlet and the outlet is long to sanitize the percolate at the outlet. The percolate tank has meander-shaped flow path between the inlet and the outlet, and is arranged below the fermenters. One of the fermenters is designed for occasional thermophilic operation. Two devices (11, 12) are provided for cleaning the percolate and are switched between the fermenter and the percolate tank, where the fermenter and the cleaning devices are switchable, so that the sanitized percolate occurring from the fermenter is guided into the one of the cleaning device and the unsanitized percolate occurring from the fermenter is guided into the other cleaning device. A heating zone, at which the percolate reaching into the percolate tank is heatable at a predetermined temperature, is provided behind the percolate inlet in the percolate tank. One of the cleaning devices is a sand trap. A heater is provided in the percolate tank and/or one and/or both cleaning devices for cleaning the percolate and is operated, so that a predetermined minimum temperature of the percolate is regulated. An INDEPENDENT CLAIM is included for a method for recovering biogas.    DESCRIPTION OF DRAWING(S) - The diagram shows a plan view of a device for recovering biogas.    Percolate tank (10)    Outlet (10b)    Percolate inlet (10c)    Cleaning devices (11, 12)    Fermenters. (13)