Tannase enzyme (EC 3.1.1.20) is an enzyme used in many biotechnological applications as in chemical, beverage, pharmaceutical and food industries. was isolated and purified from marine Aspergillus nomius GWA5 by 75% acetone fractional precipitation, followed by gel filtration in Sephadex G-100 and ion exchange chromatography on DEAE-Sephadex A-50 yielding 4.48-fold purification. Estimation of tannase molecular weight was carried out using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showing a molecular weight of 30 kDa. The highest activity (291 U/mg protein) were at pH 6.0 and 50 °C, respectively. Tannase stability was observed in acidic range (4-6) and was stable to heat treatment. In absence of its substrate it retained about 84.5% of its activity at 80 °C for 15 min. Effect of some metal ions and chelator on tannase activity was investigated. Mg 2+ activated as activator of the pure enzyme while EDTA, Cd 2+ , Pb 2+ and Hg 2+ inhibited its activity and retained about 40.78, 51.55, 30.24 and 24.55% of its activity, respectively. Promising activity of Tannase was shown in removing tannin stains of tea from clothes.