Wage inequalities between women and men have been interpreted using different factors, all of which are important, but they do not seem sufficient to understand the following paradox: women remain significantly less paid than men and wage gap has been almost stagnant for many years although girls’ level of education is higher than boys’ and earnings are supposed  to increase according to the level of education. This article, which is based on a research report completed in December 2016 entitled "Costs of professional inequalities between women and men in relation to their degree", attempts to measure the differential effect of the level of education on employment, occupations and, above all, remuneration of women and men.