A quality management system comprising: an acquiring unit (100) for acquiring concentration period information indicating a period in which an impurity included in a cleaning liquid for cleaning an object was concentrated by a concentration means; a database (200) for storing associated information associating object ID information uniquely allocated to the object with cleaning period information indicating a period in which the object was cleaned; and an identification unit (300) which, on the basis of the concentration period information acquired by the acquiring unit 100 and the associated information stored in the database (200), identifies an object that was cleaned using a cleaning liquid corresponding to the cleaning liquid supplied to the concentration means in a concentration period indicated by the concentration period information.