A device for gassing a liquid, including a rotor, which is driven to rotate and has multiple vanes for conveying the liquid, and a stator, which surrounds the rotor and has a plurality of flow channels, which each extends starting from a radially inner inlet opening adjacent to the rotor through the stator to a radially outer outlet opening and are delimited along their length by side walls, bottom surfaces, and top surfaces and can be acted on with liquid by the rotor in the region of the inlet opening, wherein between the inlet opening and the outlet opening, the side walls and/or bottom and top surfaces of the flow channels have a multitude of gassing openings, which can be acted on with compressed gas from a compressed gas source in order to introduce this gas into the flow channels. A corresponding method for gassing a liquid is also disclosed.