The plaintiff, whose name has not been made public, discovered by chance that while she was making 6,000 francs ($6,500) a month, the man she was supervising earned 10,000 francs.
She decided to leave her job and began a legal battle that has lasted a year and a half, reports newspaper Le Matin.
Her company, a small investment firm in Lausanne, sought to reach an out-of-court settlement with her, offering compensation of 1,500 francs. She refused, saying they owed her at least 21,000 francs.
She then took the case to Vaud’s Cantonal Court which ruled against her, arguing the salary difference was based on his superior language skills. In addition to French, he spoke both German and Swiss German, and was familiar with technical language.
The plaintiff then appealed the case to the Federal Supreme Court, which pronounced a favourable judgment on September 24th.
The sentence is being seen as a victory for female workers in a country where the wage gap between male and female workers spans an average at 21 percent, even though the principle of equal wages for similar work was written into the Swiss Federal Constitution in 1996.
According to the Federal Office for Gender Equality, the differential is even higher at executive level, where women’s salaries are 29.8 percent lower, according to official data from 2002.
In the European Union, European Commission statistics show that women earn on average 18 percent less than men - a gap that has barely narrowed over the last 15 years.