This study was designed to determine the optimal aging conditions after analyzing the physicochemical and microbiological properties of dry-aged chicken breast using an electric field supercooling system (EFSS). Chicken breast was aged for up 5 weeks at three different temperatures (0°C, −1°C, and −2°C). Aging and trimming loss at −2°C treatment showed lower values than at 0°C and −1°C treatments. Thiobarbituric acid reactive substances and volatile basic nitrogen in all treatments increased during the aging process but showed the lowest levels at −2°C. As a result of analysis of aerobic bacteria, it is microbiologically safe to dry-age for up to 2 weeks at 0°C and up to 3 weeks at −1°C and −2°C. Therefore, the dry-aged chicken breast with EFSS was optimally aged for 3 weeks at −2°C.