A valve for a vacuum apparatus, comprising: a first housing element and a second housing element connected with the first housing element, wherein an outer chamber is defined by the first housing element and the second housing element, wherein the first housing element has a first opening and the second housing element has a second opening in fluid communication with the first opening via the outer chamber, wherein an inner chamber is defined by the first housing element and the second housing element, wherein a membrane is disposed in the inner chamber dividing the inner chamber in a first inner chamber and a second inner chamber, thereby forming a driving mechanism, the valve being characterized in that it comprises a sealing element having: a first disk connected to a stem, wherein the stem is connected to the driving mechanism of the valve, a second disk disposed on the first disk; and a seal comprising a circular base element, wherein the base element has a non-circular cross-section having an outer side extending in an axial direction and an inner side extending radially, wherein the seal is clampingly fixed between the first disk and the second disk, wherein the sealing element is connected to the membrane via the stem of the sealing element, wherein the sealing element is movable from a first position to a second position, wherein in the first position the sealing element closes the first opening in a leaktight manner and in the second position the sealing element opens the first opening to allow a gaseous medium to flow through the valve. a first housing element and a second housing element connected with the first housing element, wherein an outer chamber is defined by the first housing element and the second housing element, wherein the first housing element has a first opening and the second housing element has a second opening in fluid communication with the first opening via the outer chamber, wherein an inner chamber is defined by the first housing element and the second housing element, wherein a membrane is disposed in the inner chamber dividing the inner chamber in a first inner chamber and a second inner chamber, thereby forming a driving mechanism, the valve being characterized in that it comprises a sealing element having: a first disk connected to a stem, wherein the stem is connected to the driving mechanism of the valve, a second disk disposed on the first disk; and a seal comprising a circular base element, wherein the base element has a non-circular cross-section having an outer side extending in an axial direction and an inner side extending radially, wherein the seal is clampingly fixed between the first disk and the second disk, wherein the sealing element is connected to the membrane via the stem of the sealing element, wherein the sealing element is movable from a first position to a second position, wherein in the first position the sealing element closes the first opening in a leaktight manner and in the second position the sealing element opens the first opening to allow a gaseous medium to flow through the valve. a first disk connected to a stem, wherein the stem is connected to the driving mechanism of the valve, a second disk disposed on the first disk; and a seal comprising a circular base element, wherein the base element has a non-circular cross-section having an outer side extending in an axial direction and an inner side extending radially, wherein the seal is clampingly fixed between the first disk and the second disk, wherein the sealing element is connected to the membrane via the stem of the sealing element, wherein the sealing element is movable from a first position to a second position, wherein in the first position the sealing element closes the first opening in a leaktight manner and in the second position the sealing element opens the first opening to allow a gaseous medium to flow through the valve.