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. <EOS>