The present invention provides a cleaning-performance evaluation system that can acquire evaluation results in real time as quantitative values without such factors as the experience of evaluators causing variations in evaluations.The present invention includes: a contamination means for administering a mock contaminant to the inside of a work chamber; a waste liquid recovery means for performing a cleaning operation and recovering a cleaning waste-liquid that contains the mock contaminant; a mist generation means for generating a mist of the cleaning waste-liquid; a collection means for collecting inspection air that includes the generated mist; and a detection means for detecting the amount of the mock contaminant included in the inspection air collected by the collection means. The present invention evaluates the cleaning operation by confirming that the amount of the mock contaminant detected by the detection means is at or below a prescribed value.