Résumé : Unaccompanied minors (UAMs) arriving in Europe to apply for asylum are a particular social group. They are children and they are migrants. The European Union (EU) and national asylum authorities, laws and rules deal with these groups in a very different way. Since the end of the XX century, migrants are increasingly described as a threat to European societies. For this reason, they are regarded as suspects, and migration policies are restrictive. Children, by contrast, are considered vulnerable, and, as such, in need for protection. This thesis investigates the way in which the EU institutions have framed UAMs and the subsequent effects of this labelling over the agency which is recognized to them by two European supranational courts, the Court of Justice of the European Union (CJEU) and the European Court for Human Rights (ECtHR). The research follows a discourse analysis methodology. Adopting a post-structuralist perspective, the EU institutions’ official documents are analyzed to identify the narratives that shape their framing of UAMs, the situation they find themselves into, and what should be done about them. Additionally, case law of the CJEU and ECtHR is mobilized to examine the effects of these narratives. This thesis demonstrates that EU institutions actually characterize UAMs both as vulnerable and as suspects. Vulnerable because they are described as victims, as passive, as having special needs and they are identified with other groups who are considered vulnerable in and by European societies. Suspects because they are presented as potentially untrustworthy, as a threat to receiving countries, and as migrants who must be prevented from coming to Europe or returned to their country of origin. However, even though they have been attributed these two characteristics by EU institutions’ narrative, this thesis also shows that the characteristics of suspicion does not factor significantly when cases involving UAMs arrive in front of European courts, be it the CJEU or the ECtHR. Indeed, both courts always focus on UAMs’ vulnerability, even for the UAMs who are almost adults. This characterization, however, has a concrete effect on the agency which is recognized to UAMs by the courts. In fact, since they consider all UAMs vulnerable, UAMs are not recognized an active agency. This research is important in a time when the issue of UAMs has acquired relevance in the European public debate. According to a post-structuralist approach, powerful institutions have a fundamental role in the creation of narratives which drive the actions of other actors. This work offers an analysis of how EU institutions framed the subject, and it can be useful for analyzing the effects of this categorization in the national systems or in European societies.