The present invention relates to a membrane pump and an apparatus comprising such a membrane pump. The membrane pump comprises a pumping chamber and a flexible member separating the pumping chamber into a first accumulation container and a second accumulation container. The flexible member is configured to be movable within the pumping chamber so as to vary a volume relationship between the first and second accumulation container. The second accumulation container is configured to receive an amount of working fluid to act on the flexible member and thus, in use, pump a first fluid from the first accumulation container. The first and the second accumulation container, each has an inlet opening for inlet of the respective fluid and an outlet opening for outlet of the respective fluid, the inlet opening being arranged on one side of the accumulation container and the outlet opening being arranged on the opposite side of the accumulation container. The flexible member is configured to show, when arranged in the pumping chamber and seen in a cross section along a plane extending through a pair of the inlet and outlet openings of the accumulation container, a thickness that is increased in a downstream direction.La présente invention concerne une pompe à membrane et un appareil comprenant une telle pompe à membrane. La pompe à membrane comprend une chambre de pompage et un élément souple divisant la chambre de pompage en un premier contenant d'accumulation et un second contenant d'accumulation. L'élément souple est configuré de façon à pouvoir se déplacer à l'intérieur de la chambre de pompage afin de faire varier la relation de volume entre les premier et second contenants d'accumulation. Le second contenant d'accumulation est configuré de façon à recevoir une certaine quantité de fluide de travail destinée à agir sur l'élément souple et ainsi, en utilisation, pomper un premier fluide à partir du premier contenant d'accumulation. Les premier et second contenants d'accumu
