Microfluidic device comprising: at least one component having channel structures formed therein which are at least partly open toward a respective component surface of the at least one component; and a film comprising an elongated opening (24; 34') via which the at least a first and a second one of the channel structures (24a, 24c; 24a, 24b) are connected to one another, the elongated opening being closed by a lid on a side facing away from the component surface, wherein the first and second channel structures are formed within the same component and each opens at least partly in the component surface thereof, the film covering the component surface of the same component such that the first and second channel structures are connected to each other via a path extending laterally along the component surface of the same component and within the elongated opening in the film, wherein the channel structures each comprise a trench portion, and the trench portions of the channel structures extend in parallel, over a length portion, along a shared extension direction in the component surface of the same component, a longitudinal direction of the elongated opening (34; 34') extending in a manner that is transverse to the shared extension direction, and the channel structures projecting into the length portion to different degrees from one and/or two sides, so that a variation of the elongated opening within the film leads, in its position along the extension direction and along the longitudinal direction, and in its length along the longitudinal direction, to at least four different combinations of channel structure connections, wherein within a combination of channel structure connections, any third channel structures which are formed within the same component as the first and second channel structures and may not be connected to the first and second channel structures via the opening do not adjoin the elongated opening, wherein the channel structures comprise depressions in the component surface of the same component, said depressions being at least partly covered by the film, wherein the film is adhered to the component surface of the same component; characterized in that the path leading through the elongated opening within the film is closed, on a side facing away from the component surface of the same component, with a porous membrane as the lid, and wherein the path leading through the opening within the film comprises a flow cross-section which is reduced as compared to the channel structures, so that degassing via the porous membrane, which is not wetted by a liquid, is promoted due to a local increase in pressure resulting from the reduced cross-section, wherein a thickness of the film is small enough, in the area of the opening, to prevent that gas bubbles in water may pass the path without touching the porous membrane. at least one component having channel structures formed therein which are at least partly open toward a respective component surface of the at least one component; and a film comprising an elongated opening (24; 34') via which the at least a first and a second one of the channel structures (24a, 24c; 24a, 24b) are connected to one another, the elongated opening being closed by a lid on a side facing away from the component surface, wherein the first and second channel structures are formed within the same component and each opens at least partly in the component surface thereof, the film covering the component surface of the same component such that the first and second channel structures are connected to each other via a path extending laterally along the component surface of the same component and within the elongated opening in the film, wherein the channel structures each comprise a trench portion, and the trench portions of the channel structures extend in parallel, over a length portion, along a shared extension direction in the component surface of the same component, a longitudinal direction of the elongated opening (34; 34') extending in a manner that is transverse to the shared extension direction, and the channel structures projecting into the length portion to different degrees from one and/or two sides, so that a variation of the elongated opening within the film leads, in its position along the extension direction and along the longitudinal direction, and in its length along the longitudinal direction, to at least four different combinations of channel structure connections, wherein within a combination of channel structure connections, any third channel structures which are formed within the same component as the first and second channel structures and may not be connected to the first and second channel structures via the opening do not adjoin the elongated opening, wherein the channel structures comprise depressions in the component surface of the same component, said depressions being at least partly covered by the film, wherein the film is adhered to the component surface of the same component; characterized in that the path leading through the elongated opening within the film is closed, on a side facing away from the component surface of the same component, with a porous membrane as the lid, and wherein the path leading through the opening within the film comprises a flow cross-section which is reduced as compared to the channel structures, so that degassing via the porous membrane, which is not wetted by a liquid, is promoted due to a local increase in pressure resulting from the reduced cross-section, wherein a thickness of the film is small enough, in the area of the opening, to prevent that gas bubbles in water may pass the path without touching the porous membrane.