A device tests at least one quality parameter of a fluid in fluid apparatuses, e.g., working cylinders (10), hydraulic accumulators, valves, filter housings, pressure tubes, which at least temporarily accommodate a given fluid volume in at least one fluid chamber (12, 14). The fluid volume is stored in a storage unit (16) with the aid of a control mechanism (16) after being discharged from the fluid apparatus in order to be redirected from there into a measuring element (22, 24) to verify the respective quality parameter of the fluid. The inventive device makes it possible to specifically obtain a statement about the operability of the respective fluid apparatus within a very short period of time.