Dish washing machine with steam generator and method of controlling same

Dish washing machine including a steam generator, which supplies steam during the washing procedure to aid in the washing of items in the dish washer, and a method for controlling the same. The dish washing machine capable of discharging residual water from the steam generator to remove impurities in the water contained therein. Discharging the residual water in the steam generator may be performed prior to, during or after the washing procedure in such a manner so as to protect other components from damage due to the high temperatures associated with the residual water.