A gas pump including a first housing part (1) comprising a sealing surface (6); a second housing part (2) comprising a sealing surface (7); a delivery chamber (3) comprising an inlet (4) and an outlet (5) for a gas; and a delivery device (11, 12), which can be moved within the delivery chamber (3), for delivering the gas, wherein the housing parts (1, 2) are joined to each other such that they at least partially enclose the delivery chamber (3) over a circumference of the chamber, and such that their sealing surfaces (6, 7) abut each other in order to seal off the delivery chamber (3), and wherein a sealing recess (9) extends in at least one of the sealing surfaces (6, 7) around the delivery chamber (3) and is filled with a sealing liquid when the gas pump is in operation.