The purpose of this study is empirically analyzing the effects of external factors(user knowledge, service characteristics, security), perceived risk, trust, ease of use, and usefulness on continuous customer acceptance in Internet banking. To achieve the goal, we develop the extended Technology Acceptance Model(Ex-TAM) based in the theoretical backgrounds of the Technology Acceptance Model(TAM). To test the new model(Ex-TAM), path analysis is performed by AMOS 4.0 package as a statistical tool. The finding indicate that 4 factors(service characteristics, ease of use, usefulness, trust) are significant. However, 2 factors(security, perceived risk) are not significant, user knowledge is partly significant.