A membrane pump (1, 1′, 1″), in particular for use in the exhaust gas tract of a combustion engine (70), comprising a pressure housing (2), the internal volume (4) of which is subdivided by a number of resiliently deformable membranes (6) into a plurality of sub-volumes (8, 10) separated from one another on the gas side, wherein a biasing force is applied to the or each membrane (6) in such a way that in the pressure-free state the sub-volume (8) forming the primary side has a minimum value in relation to the deformability of the or each membrane (6), is to act so as particularly to increase effectiveness during use in the exhaust system of a combustion engine (70). For this purpose, according to the invention, a leaf spring (36) is provided as a restoring spring for applying the biasing force to the membrane (6).