The aim of this bachelor thesis is to study how school librarians working in elementary and middle schools describe and obtain their competence, and how they work to make their competence visible through collaborations within the school organization. The empirical material consists of five semi structured interviews with school librarians. The theoretical framework consists of a competence model which divides competence into five different categories and the two concepts; formal and real legitimacy. The method of analysis is qualitative content analysis which is being used to code the empirical material. The result of this study shows that school librarians have a wide range of skills from all the categories in the competence model and that different sets of skills are being used depending on the work task. Reading promotion skills and social competence is especially prominent in the result. The study shows that they obtain their competence through formal education in Library and Information Science and that they continue to develop their skills throughout their professional life. The results show that the competence of school librarians are made visible for example through collaboration with teachers and that being an integral part of the school organization is vital for enabling these collaborations.