The sociology of „people who run europe“ is curiously absent of the majority of the european studies, and specialy the process of their professionnalisation. This contribution would like to present some benefits of the sociology of professions in order to understand the différenciation of a European political space. Founded on the results published in the collective book Les métiers de l'Europe, it identifies three directions that could help to better understand the differenciation process of the european political space : the competition between the group and the out-group of euro-proferssionnals, their internal competition and their effects on the closure of the field, the effects of professional situations and practices.