This article formulates an empirical model for salary determination, which permits the identification of the depreciation rate of the stock of professional qualifications. The analysis is implemented using the 1994 European Community Household Panel data referring to Spanish salaried males. The depreciation rate of the stock of qualifications is estimated at a narrow interval centred at 1 percent. Empirical evidence also suggests that although the depreciation rate does not vary according to the level of education, it does so depending on unemployment spells endured by the worker in recent years and on whether the worker has undertaken training courses.