The purpose of this study was to examine the meaning and the essence of the on-site supervision experience of an art therapy master s degree student in institution-based art therapy. There were 12 participants in total: 10 students in a master s degree art therapy program and two graduate students that had experienced on-site supervision during their master s degree course. Data was gathered for 6 months, from June to November 2016, and researchers indentified 11 essential themes and 30 sub-themes after applying Max van Manen s Hermaneutic Phenomenological Research Method. The study suggested the following conclusions: first, the participants had more clarity on their sessions with the aid of the on-site supervisor and grew as beginning art therapists by learning various things, including other trainings and communicating with institutions. Second, participants expressed a simultaneous sense of security and nervousness and experienced different feelings and impressions. Third, participants started to look into their future and began to think about their career as art therapists. In addition, they were able to acquire a broader perspective toward art therapy with the help of the on-site supervision, since it incorporates both theory and practice. Fourth, participants expressed a recognition that the clients, on-site supervisors, and participants have grown together as a result of the work they have done together.