This paper investigates the gender wage gap in Spain by analyzing data from the 2018 Spanish Structure of Earnings Survey to quantify the gap and decompose it into the explained and unexplained gaps using three different "discrimination- free" distributions (Reimers, Cotton and Jann). As covariates, in addition to seniority at work, studies and type of contract, common in the literature, they introduce occupation. The study treats full-time workers separately from part-time workers. This distinction is important due to the characteristics of the Spanish labor market, where part-time contracts predominate among women. The results show that part-time female employees are less discriminated against than full-time female employees, and that at lower levels of education and in lower skilled occupations The results show that part-time workers are less discriminated against and that at lower levels of education and in lower-skilled occupations, women's wages are closer to those of men. [ABSTRACT FROM AUTHOR]