1. Substantial Chamber capacity This sterilizer has a practical sized chamber and is very effective to sterilize a bigger loads or more loads, and is a typical S-Class which sterilizes the medical instruments economically by applying the saturated steam generated from water by heater in the chamber to sterilize and removing air from the chamber by gravity. Dry performance after sterilization was improved innovatively because it need not to open the door during dry process by adopting vacuum drying system. This product has obtained the certificate of CE mark from the authoritative notified body in Europe. 2. Variable Cycle Programs and Self-Diagnosis Program 5 types of cycle program that is composed of frequently using typical sterilization parameters are embedded in the controls of sterilizer. Therefore operator can select a proper cycle conveniently for sterilizing a load and change the parameters of program easily according to the sterilizing condition. In case of the liquid cycle, the innovative method, that the residual steam after sterilization would not exhaust but cool down and condense into water naturally, has been used which enables to prevent liquid from boiling up or breaking the bottle. In addition, the redrying cycle program is embedded for drying function only. The self-diagnosis program generates the warning signal, displays the error code on the control panel and aborts the executing cycle for safety automatically in case that any operating error has occurred during cycle executing.