A method of controlling a dishwasher including a tub defining a washing chamber, a spray nozzle for spraying the washing water into the washing chamber and a steam generating device provided at a lower portion of the tub to supply steam into the tub, the method comprising: performing a main washing for washing the dishes using washing water containing detergent; performing a rinsing (120, 130) for rinsing the dishes; and supplying steam using the steam generating device during the main washing or both the main washing and the rinsing, wherein: performing the main washing includes spraying washing water using the spray nozzle (113, 114) and allowing food residues adhered to the dishes to absorb water, the allowing food residues to absorb water being performed after terminating the spraying washing water (113, 114) and said spraying washing water (113, 114) and allowing food residues to absorb water being repeatedly performed during the main washing, characterized in that the method further comprises: supplying the water used for generating the steam to the steam generating device and heating the supplied water in the steam generating device when the spraying washing water starts, wherein the supply of steam starts after the supply of water used for generating the steam is finished, and wherein the steam is continuously supplied until the allowing food residues to absorb water is finished, so as to prevent stopping the spraying steam during the step of allowing the food residues to absorb water. performing a main washing for washing the dishes using washing water containing detergent; performing a rinsing (120, 130) for rinsing the dishes; and supplying steam using the steam generating device during the main washing or both the main washing and the rinsing, wherein: performing the main washing includes spraying washing water using the spray nozzle (113, 114) and allowing food residues adhered to the dishes to absorb water, the allowing food residues to absorb water being performed after terminating the spraying washing water (113, 114) and said spraying washing water (113, 114) and allowing food residues to absorb water being repeatedly performed during the main washing, characterized in that the method further comprises: supplying the water used for generating the steam to the steam generating device and heating the supplied water in the steam generating device when the spraying washing water starts, wherein the supply of steam starts after the supply of water used for generating the steam is finished, and wherein the steam is continuously supplied until the allowing food residues to absorb water is finished, so as to prevent stopping the spraying steam during the step of allowing the food residues to absorb water. performing the main washing includes spraying washing water using the spray nozzle (113, 114) and allowing food residues adhered to the dishes to absorb water, the allowing food residues to absorb water being performed after terminating the spraying washing water (113, 114) and said spraying washing water (113, 114) and allowing food residues to absorb water being repeatedly performed during the main washing, characterized in that the method further comprises: supplying the water used for generating the steam to the steam generating device and heating the supplied water in the steam generating device when the spraying washing water starts, wherein the supply of steam starts after the supply of water used for generating the steam is finished, and wherein the steam is continuously supplied until the allowing food residues to absorb water is finished, so as to prevent stopping the spraying steam during the step of allowing the food residues to absorb water.