Recruiting businesses do not all give the same place to new entrants, to whom they do not all give the same career opportunities. So alongside individual determinants, the firm plays a role in building new entrants' career paths. This analysis uses longitudinal data to show that the probability of having a stable job in the business of first employment three years after the end of studies depends significantly on the initial business sector, even as regards those in certain cross-functional jobs. Given the same level of qualifications, gender and business size, stabilisation with the first employer is more frequent in the aeronautic, shipbuilding and rail engineering, energy, air transport, finance, real estate, health, post and telecommunications, motor vehicle repairs and consultancy-assistance services sectors. For those who are mobile, the sector of initial employment maintains an influence, albeit moderate, on the probability of being unemployed three years later. A specific shelter-from-unemployment effect appears in just two sectors: health and education. These findings can be interpreted from the point of view of inclusion or not in internal markets and also in professional markets.