A device (1) for separating sulphur dioxide from a gas has an inlet (2) for the gas (4) and an outlet (42) for gas (40), from which sulphur dioxide has been separated. An apertured plate (20) is arranged between the inlet (2) and the outlet (42) and allows the gas (4) to pass from below. On its upper side (22), the apertured plate supports a flowing layer (24) of absorption liquid. An inlet duct (12) connects a container (6) for absorption liquid to the upper side (22) of the apertured plate (20). A means (10) conveys the absorption liquid (8) from the container (6), through the inlet duct (12), to the upper side (22) of the apertured plate (20) and along the apertured plate (20). The device also has an outlet box (30) for collecting the absorption liquid (8) flowing over the apertured plate (20) and at least one distribution means (34), which is arranged to contact the gas (4) which is supplied to the device (1) through the inlet (2) with the liquid (8) flowing from the outlet box (30) to the container (6) before the gas (4) passes through the apertured plate (20).