Cartridge for containing a fluid to be nebulized by a nebulizer, the cartridge comprising an outer container of the cartridge with a longitudinal or central axis and a closure with an opening for receiving a connecting element of the nebulizer for fluidically connecting the cartridge to the nebulizer, wherein the cartridge defines the axis which runs centrally through the opening, wherein the closure comprises an integrally formed closure part forming a sealing (S1, S7) with an integrally formed portion of the outer container of the cartridge as well as a sealing (S5, S6) with the connecting element and/or a holder thereof, and wherein the closure part comprises an inner portion and a preferably flange-like outer portion protruding radially therefrom, wherein the outer container comprises the integrally formed portion which protrudes radially towards the longitudinal or central axis of the container and which forms an opening which receives the closure, characterized in that the integrally formed closure part forms sealings (S1, S7) with the outer container of the cartridge by direct abutment against the outer container both in the axial direction and the radial direction of the cartridge, wherein the closure part forms an - axial sealing with an axial abutment face of the integrally formed portion of the outer container and - a radial sealing between an outer diameter of the inner portion of the closure part and an inner diameter of the integrally formed portion of the outer container, and that the cartridge comprises a securing element securing the closure to the container, in particular in the axial direction, wherein the closure part is pressed onto the outer container, in particular in the axial direction, by means of the securing element and/or wherein the closure part is clamped between the securing element and the outer container. the cartridge comprising an outer container of the cartridge with a longitudinal or central axis and a closure with an opening for receiving a connecting element of the nebulizer for fluidically connecting the cartridge to the nebulizer, wherein the cartridge defines the axis which runs centrally through the opening, wherein the closure comprises an integrally formed closure part forming a sealing (S1, S7) with an integrally formed portion of the outer container of the cartridge as well as a sealing (S5, S6) with the connecting element and/or a holder thereof, and wherein the closure part comprises an inner portion and a preferably flange-like outer portion protruding radially therefrom, wherein the outer container comprises the integrally formed portion which protrudes radially towards the longitudinal or central axis of the container and which forms an opening which receives the closure, characterized in that the integrally formed closure part forms sealings (S1, S7) with the outer container of the cartridge by direct abutment against the outer container both in the axial direction and the radial direction of the cartridge, wherein the closure part forms an - axial sealing with an axial abutment face of the integrally formed portion of the outer container and - a radial sealing between an outer diameter of the inner portion of the closure part and an inner diameter of the integrally formed portion of the outer container, and that the cartridge comprises a securing element securing the closure to the container, in particular in the axial direction, - axial sealing with an axial abutment face of the integrally formed portion of the outer container and - a radial sealing between an outer diameter of the inner portion of the closure part and an inner diameter of the integrally formed portion of the outer container, and that the cartridge comprises a securing element securing the closure to the container, in particular in the axial direction, wherein the closure part is pressed onto the outer container, in particular in the axial direction, by means of the securing element and/or wherein the closure part is clamped between the securing element and the outer container.