The purpose of the present study was to examine the volunteer experiences of university students as mental health supporters in elementary schools. Semi-structured interview was conducted to 13 students who participated in the volunteer activity, and obtained qualitative data were analyzed using the Modified Grounded Theory Approach. As a result, nine categories emerged, and the process of volunteer experiences and supporting factors for this process were identified. Based on these findings, support system for student volunteers was discussed from the perspectives of university and elementary schools which accept student volunteers.