The article analyzes the key substantive characteristics of the principle of professionalism and competence of civil servants as one of the foundations of legal relations related to the admission to and performance of state service. It is noted that a necessary condition for the manifestation of professionalism is that its content as an internal quality of an individual must correspond to the structure of the competence of the position being filled or planned to be filled. It is concluded that the business qualities of professionalism and competence are distinguished by their dynamics: acquired as a result of obtaining an education in a specific specialty or field of study, they need to be improved, constantly updated, and supplemented in accordance with the requirements for qualifications for filling certain positions in the civil service at a specific time.