A device for cleaning a fluid contaminated with oil, comprising a container having an inlet for the contaminated fluid and an outlet for the cleaned fluid, wherein the container contains a packing of a material that can absorb the oil, through which material a contaminated fluid can flow in the intentional use state of the device to leave the contaminants behind, characterized in that • said packing is formed by a package-like tangle of keratin structures that have a three-dimensionally irregular orientation and are randomly distributed in all three dimensions, which keratin structures are enclosed by a closed container edge between the inlet and outlet (5, 6) and fit against it in a fluid-tight way in the use state of the device, • wherein the tangle of the keratin structures is essentially uniformly compacted along the path of the fluid between the inlet and outlet (5, 6), wherein the compaction is such that the keratin structures absorb at least 6.5 times their own weight of oil from the fluid before saturation of the keratin structures with oil occurs, • wherein said packing is formed by a separate absorption unit that can be employed in a predetermined reception space of the container • wherein a respective first absorption unit present in the reception space can be replaced from the reception space of the container by means of an exchange device assigned to said container automatically by a respective second absorption unit, • wherein the replacement takes place as soon as the first absorption unit exhibits a predetermined degree of oil saturation, wherein the degree of saturation of the absorption unit can be determined automatically by means of an optical recognition device attached to the container or to the outlet, • wherein the recognition device is connected with a PLC (programmable logic controller), which addresses the exchange device through a respective connection for the automated exchange of the absorption units, and optionally stops the continuous in-flow or out-flow of the fluid by addressing the respective valve in the inlet or outlet in the period of exchanging, • wherein the respective first absorption unit can be automatically supplied to a collection point through a transport device after the exchange has taken place. • said packing is formed by a package-like tangle of keratin structures that have a three-dimensionally irregular orientation and are randomly distributed in all three dimensions, which keratin structures are enclosed by a closed container edge between the inlet and outlet (5, 6) and fit against it in a fluid-tight way in the use state of the device, • wherein the tangle of the keratin structures is essentially uniformly compacted along the path of the fluid between the inlet and outlet (5, 6), wherein the compaction is such that the keratin structures absorb at least 6.5 times their own weight of oil from the fluid before saturation of the keratin structures with oil occurs, • wherein said packing is formed by a separate absorption unit that can be employed in a predetermined reception space of the container • wherein a respective first absorption unit present in the reception space can be replaced from the reception space of the container by means of an exchange device assigned to said container automatically by a respective second absorption unit, • wherein the replacement takes place as soon as the first absorption unit exhibits a predetermined degree of oil saturation, wherein the degree of saturation of the absorption unit can be determined automatically by means of an optical recognition device attached to the container or to the outlet, • wherein the recognition device is connected with a PLC (programmable logic controller), which addresses the exchange device through a respective connection for the automated exchange of the absorption units, and optionally stops the continuous in-flow or out-flow of the fluid by addressing the respective valve in the inlet or outlet in the period of exchanging, • wherein the respective first absorption unit can be automatically supplied to a collection point through a transport device after the exchange has taken place.