NOVELTY - A bioscrubber (1) comprises an inlet (9) for dirty gas and an outlet (10) for cleaned gas; circulated scrubbing liquid containing water and microorganisms; at least one mass-transfer zone where a phase change of dirty gas is effected from gas phase to liquid phase; an irrigation device (4) for irrigating mass-transfer zone with scrubbing liquid; a collection tank (8) for collecting scrubbing liquid and activating microorganisms; at least one package of vertical and mutually adjacent tubes (11) in mass-transfer zone; and cleaning device e.g. rotary sprinkler for cleaning tubes.    USE - For purifying dirty gas (claimed) containing water-insoluble or slightly water-soluble substances.    ADVANTAGE - By using tube packages, instead of conventional packings, together with the cleaning device, the problem of blockage can be effectively prevented. The tube packages are relatively inexpensive and simple to produce. Due to vertical arrangement of the tubes, the scrubbing liquid cannot be distributed transversely, and blockages in the tubes can be readily eliminated. Due to the reduced risk of blockage, additives or solvents such as, oil-like substances can be added to the scrubbing liquid, because of which the separation rates can be increased for slightly water-soluble substances. Thus, an efficient cleaning of dirty gases, which contain slightly water-soluble or water-insoluble and water-soluble substances can be achieved.    DETAILED DESCRIPTION - A bioscrubber (1) comprises an inlet (9) for dirty gas and an outlet (10) for cleaned gas; circulated scrubbing liquid containing water and microorganisms for degrading substances to be separated off from the dirty gas; at least one mass-transfer zone where a phase change of the dirty gas is effected from a gas phase to a liquid phase; an irrigation device (4) for irrigating the mass-transfer zone with the scrubbing liquid; a collection tank (8) for collecting the scrubbing liquid and for activating the microorganisms; at least one package of vertical and mutually adjacent tubes (11) disposed in mass-transfer zone; and a cleaning device e.g. rotary sprinkler for cleaning the tubes disposed over the package. The scrubbing liquid contains thermophilic microorganisms or mesophilic microorganisms, and solvents for dissolving polar and organic substances. The bioscrubber further comprises a mist separator disposed upstream of the outlet, and an aeration device (6) disposed in the collection tank.    DESCRIPTION OF DRAWING(S) - The figure shows a sectional view of the bioscrubber.    bioscrubber (1)    irrigation device (4)    aeration devices (6)    stirring devices (7)    collection tank (8)    inlet (9)    clean gas outlet (10)    tubes. (11)