Method for cleaning a gas stream, in particular an air stream, guided in a circuit, in which the gas stream is guided through at least one filter stage, in which use is made of an adsorption filter device with a filter medium through which the gas stream flows as at least one filter stage, wherein use is made of a filter apparatus for filtering a gas stream laden with impurities, and a) an adsorption filter device comprising a filter medium is flowed through by the gas stream in such a way that the gas stream comes into contact with filter medium, wherein the filter medium adsorbs impurities at an adsorption temperature in an adsorption temperature range and desorbs impurities again at a desorption temperature in a desorption temperature range; b) filter medium, by means of at least one regeneration device, is brought to a desorption temperature, so that the filter medium is freed of previously adsorbed impurities; wherein c) the adsorption filter device comprises at least one first filter module (88; 36) and one second filter module (88; 36), in each case having its own module housing, in which filter medium is present in each case and which are in each case flowed through by the gas stream, wherein each filter module (36; 88) is a filter unit or comprises multiple filter units which are arranged in a common vertical column, wherein the filter units have their own housing, in which the filter medium is arranged, and are stacked one on the other and one against the other to form a filter wall; d) the regeneration device is configured in such a way that the first filter module (88; 36) is regenerated independently of the second filter module (88; 36); e) the regeneration unit comprises a desorption-fluid feed unit and a desorption-fluid discharge unit which are positioned on two sides of a filter module (88; 36) in such a way that the latter is flowed through at least regionally by desorption fluid; f) the desorption-fluid feed unit comprises a movable desorption-fluid outlet carriage (66; 92) and the desorption-fluid discharge unit comprises a movable desorption-fluid inlet carriage, said carriages being positioned on opposite sides of a filter module (88; 36) in such a way that desorption fluid flows from the desorption-fluid outlet carriage (66; 92) to the desorption-fluid inlet carriage through the filter module (88; 36). a) an adsorption filter device comprising a filter medium is flowed through by the gas stream in such a way that the gas stream comes into contact with filter medium, wherein the filter medium adsorbs impurities at an adsorption temperature in an adsorption temperature range and desorbs impurities again at a desorption temperature in a desorption temperature range; b) filter medium, by means of at least one regeneration device, is brought to a desorption temperature, so that the filter medium is freed of previously adsorbed impurities; wherein c) the adsorption filter device comprises at least one first filter module (88; 36) and one second filter module (88; 36), in each case having its own module housing, in which filter medium is present in each case and which are in each case flowed through by the gas stream, wherein each filter module (36; 88) is a filter unit or comprises multiple filter units which are arranged in a common vertical column, wherein the filter units have their own housing, in which the filter medium is arranged, and are stacked one on the other and one against the other to form a filter wall; d) the regeneration device is configured in such a way that the first filter module (88; 36) is regenerated independently of the second filter module (88; 36); e) the regeneration unit comprises a desorption-fluid feed unit and a desorption-fluid discharge unit which are positioned on two sides of a filter module (88; 36) in such a way that the latter is flowed through at least regionally by desorption fluid; f) the desorption-fluid feed unit comprises a movable desorption-fluid outlet carriage (66; 92) and the desorption-fluid discharge unit comprises a movable desorption-fluid inlet carriage, said carriages being positioned on opposite sides of a filter module (88; 36) in such a way that desorption fluid flows from the desorption-fluid outlet carriage (66; 92) to the desorption-fluid inlet carriage through the filter module (88; 36).