Patent ID: 8239990

Claim:
A method of machine washing comprising: containing washing water in a water reservoir where articles for washing are located; sterilizing the washing water introduced from the water reservoir through an electrolysis process by a sterilizer; and circulating the washing water introduced from the water reservoir by a circulator while it is being sterilized and the sterilized washing water is discharged into the water reservoir, the sterilizer being positioned higher than the water level of the washing water so that the washing water is only circulated in the sterilizer during operation of the circulator, wherein the sterilizing comprises supplying electric current to a first electrode including Ag and a second electrode including a metal having an ionization tendency lower than the ionization tendency of Ag; and switching the polarity of the electric current applied to the first and second electrodes based on a desired mode of operation of the sterilizing, wherein the sterilizer is positioned higher than the water level of the washing water and the washing water is prevented from contacting the electrodes during non-operation of the circulator.