comparison with the very characteristic microlithic and geometric arrowheads, mesolithic tools remain marginal in lithic studies. This situation is explained by its atypical attributes which limits the relevance of morphological and typological approaches. This PhD thesis proposes to redefine toolkits from a techno-functional perspective thanks to use-wear approach, with the aim of considering these objects in a more complete cycle of activities. The four main corpuses considered here are dated to the Early Mesolithic (10th-7th millennium BC) and are all located in Northern France and Belgium. The analysis of these lithic assemblages made it possible to highlight the importance of unretouched tools which constitute the majority of the objec...