A dishwasher, in which a reservoir provided with an electrolyzer is connected to a water collector via a flow path change valve, and wash water in the reservoir is electrolyzed by the electrolyzer during non-operation of the wash water, to generate sterilizing water and to circulate the sterilizing water into the dishwasher, thereby achieving an enhancement in sterilizability of the dishwasher. A method for controlling a dishwasher makes it possible to suppress propagation of microorganisms left in the dishwasher and to remove organic substances, using a sterilizing agent or high-temperature water. It is also possible to reduce generation of offensive odour caused by decomposition of bacteria, through a reduction in the amount of bacteria in the dishwasher. Since sterilization of the dishwasher is automatically carried out, enhanced user convenience is provided.