A membrane filter for submerged operation for filtering a liquid, the membrane filter comprising: membrane units and a gas distribution system for distributing a gas to the membrane units and flushing the membrane units, wherein each of the membrane units includes a respective gas inlet opening and at least one membrane element , and wherein each of the membrane elements has the following features: - membranes for filtering a liquid permeate from the liquid, - a permeate collection cavity connected to permeate sides of the membranes , and a permeate outlet configured to drain the permeate from the permeate collection cavity , and wherein the gas distribution system includes exactly one gas outlet for each membrane unit , the exactly one gas outlet configured to exhaust the gas from the gas distribution system into the respective gas inlet opening of the membrane unit , characterized in that the gas distribution system includes the following features: - a downward open tub including a base arranged at a top of the tub and forming a boundary for the gas , and - a gas inlet configured let the gas into the tub , wherein the gas outlets are configured downward open in a lateral wall of the tub , and the membrane units respectively include a downward open gas collection cavity below the at least one membrane element , and the membrane units respectively include a geyser element below the at least one membrane element , the geyser element including an outlet device configured for a pulsating outlet of the gas in an upward direction from the gas collection cavity , wherein the geyser element includes the gas inlet opening at a bottom of the geyser element . membrane units and a gas distribution system for distributing a gas to the membrane units and flushing the membrane units, wherein each of the membrane units includes a respective gas inlet opening and at least one membrane element , and wherein each of the membrane elements has the following features: - membranes for filtering a liquid permeate from the liquid, - a permeate collection cavity connected to permeate sides of the membranes , and - membranes for filtering a liquid permeate from the liquid, - a permeate collection cavity connected to permeate sides of the membranes , and a permeate outlet configured to drain the permeate from the permeate collection cavity , and wherein the gas distribution system includes exactly one gas outlet for each membrane unit , the exactly one gas outlet configured to exhaust the gas from the gas distribution system into the respective gas inlet opening of the membrane unit , characterized in that the gas distribution system includes the following features: - a downward open tub including a base arranged at a top of the tub and forming a boundary for the gas , and - a gas inlet configured let the gas into the tub , - a downward open tub including a base arranged at a top of the tub and forming a boundary for the gas , and - a gas inlet configured let the gas into the tub , wherein the gas outlets are configured downward open in a lateral wall of the tub , and the membrane units respectively include a downward open gas collection cavity below the at least one membrane element , and the membrane units respectively include a geyser element below the at least one membrane element , the geyser element including an outlet device configured for a pulsating outlet of the gas in an upward direction from the gas collection cavity , wherein the geyser element includes the gas inlet opening at a bottom of the geyser element . <EOS>