Described and depicted is a gas scrubber, in particular for desulphurising flue gases, preferably for installation on a ship, having a scrubber housing and a gas pipe arranged underneath the scrubber housing for guiding the gas to be scrubbed in the scrubber housing, wherein the scrubber housing has a scrubber chamber delimited by a scrubber base, a scrubber head and a scrubber shell provided between the scrubber base and the scrubber head. In order to achieve a more reliable operation, it is provided that a gas supply for the lateral introduction of gas via at least one opening into the scrubber chamber is provided in the region of the scrubber shell.