Provided is a sterilization method and apparatus for medical instruments. In the method, a solution containing chlorine and having a temperature of about 60° C. or more is prepared. An electrode is disposed in a container containing the solution and the medical instrument is immersed in the solution such that the medical instrument is disposed over the electrode. The solution is electrolyzed by applying a current to the electrode to generate sterilizing components of free chlorine comprising hypochlorous acid, hydrogen peroxide (H2O2), OH radical, and ozone (O3) and sterilize the medical instrument by the components which move up in the opposite direction of gravity from the electrode.
