It has been indicated that there is a connection between SNS usage and psychological well-being. This study investigated whether the use of SNS could alleviate depression during the COVID-19 quarantine period. Sixty-one participants completed a self-report survey on loneliness, Instagram use, and depression at different time points(during the self-isolation and after the release of self-isolation). Hierarchical regression analyses were conducted on each of the time points. The results revealed that in addition to loneliness, the effect of SNS use on depression was significant only during the self-isolation period. The results suggest that when face-to-face social contact is impossible, using SNS may strengthen the depression rather than alleviate it.