Abstract: A filter unit for integration in an oil-water-separating device for removing oil-containing constituents from an oil-water mixture includes a housing which separates a filter interior from an environment, there being in the filter interior filter material for at least partially removing oil from the oil-water mixture. An inflow opening is provided, and the housing has, downstream of the filter material, an outflow opening for providing an outflow of cleaned liquid from the filter interior. The filter unit is a filter cartridge for detachable connection to and disconnection from the oil-water-separating device. Moreover, the outflow opening of the housing is closable by an automatic filter cartridge closure that is moveable from a closed to an open state. A base unit of an oil-water-separating device for removing oil-containing constituents from an oil-water mixture, and an oil-water-separating device for removing oil-containing constituents from an oil-water mixture are also related.