Abstract: A scrubber comprises a casing (1) with an inlet (2) and an outlet (3) for flue gases, and with an outlet (4) for water and substances separated from the flue gases, and water injection nozzles. The casing (1) is divided, by means of a partition having a throughflow opening for flue gases, into an evaporation zone (11) in which injected water is caused to cool the flue gases by heat absorption and evaporation, simultaneously as the water adsorbs any substances carried along by the flue gases, and a condensation zone (12) in which flue gases and steam from said first zone are condensed. The flue gas outlet from the condensation zone is provided with a drop separator (8), and the partition (151) separating the two zones is arranged as a collector of water which has not evaporated in said evaporation zone and which by means of a pump (16) and further nozzles (17), is reinjected into said evaporation zone (11).