In this study, antimicrobial and anti-oxidative activities were tested on skin inflammation-causing microbes (S. epidermidis, P. acnes, P. ovale, M. furfur, and C. albicans) using supercritical green tea extract. According to the antimicrobial test, S. epidermidis, P. acnes, P. ovale, and M. furfur were 14.8 mm, 18.9 mm, 16.3 mm and 18.3 mm respectively. In terms of Minimal Inhibitory Concentration (MIC), S. epidermidis, P. acnes, P. ovale, M. furfur and C. albicans were 26.2 μg/mL, 18.2 μg/mL, 22.5 μg/mL, 16.1 μg/mL, and 35.6 μg/mL respectively. In terms of DPPH radical scavenging activity, 84.28% was observed at 500 μg/mLwith 67.03±0.39 μg/mL of IC50(μg/mL). As a result, free radical scavenging activity was found. Total polyphenol and total phenol contents were 105.4±0.69 mg each, while total flavonoid content was 295.02±0.41 mg. In terms of nitrite scavenging activity, 68.71% was detected at 500 μg/mL. This study was conducted in accordance to all relevant laws and the results show that green tea supercritical extracts had significant effects on the antimicrobial and anti-oxidant activity of skin inflammation-causing microorganisms, P. acnes, with regards to hot water extraction. Further results indicate improvement in skin disorders with regards to cosmetic containing supercritical extracts of green tea as a raw material.