A cooling device includes a cooling unit (10) through which a fluid to be cooled, especially hydraulic oil, can flow and a filter unit (12) for filtering fluid. The cooling unit (10) and the filter unit (12) are joined together as one piece. The filter unit (12) is placed together with the cooling unit (10) inside a device housing (14). The cooling device can be constructed in a manner that is considerably more compact and lighter, while having an output that is comparable to that of prior art solutions.