`titrebThe disappearance of girls from information technology studies : consequences of a change of representation`/titrebAmong the scientific and technical studies, the evolution of the information technology discipline has attracted attention because the proportion of women has been in decline since the end of 1980. To try to understand the reasons for this remarkable regression, this article is based on two research fields : a thesis in sciences of education in progress and an investigation which lies within the scope of the framework of research commissioned by the service of women’s rights and equality. We will look at how the population of information technology specialists has evolved over time, then how the perception of the information technology specialist and the computer changed during the1990s. If the model of the hacker is as old as the invention of the first computers, it became characteristic of the representations of the work of the information technology specialist with the generalisation of the microcomputer. Before the 1990s, information technology was perceived so much as a technical trade of the tertiary sector, women were able to join in comparatively large numbers. But with the generalisation of the microcomputer, the model of the hacker spread amongst the public. This model, culturally familiar with boys, desirable even, activating the power phantasies in which boys are educated, became hostile to girls. They then abandoned information technology studies.