A dishwasher control method for a dishwasher, the dishwasher comprising: a sump; a pump for supplying water stored in the sump to an injection arm (711, 713, 715); a pump heater provided in the pump and for heating the water; the method comprising: a main-washing cycle in which one or more washing objects which are held in a tub are washed; a rinsing cycle in which the washing objects washed in the main-washing cycle are rinsed by injecting wash water; and a drying cycle in which the washing objects rinsed in the rinsing cycle are dried, wherein the main-washing cycle comprises, a pre-steam water supply step in which water is supplied to the sump so as to supply steam to the tub; a pre-steam supply step in which the supplied water is heated to generate steam by operating the pump heater and supplying the steam to the tub; a main-wash water supply step in which wash water for washing is supplied to the sump, without draining remaining water supplied in the pre-steam water supply step; a main-washing step in which the washing objects are washed by circulating the supplied wash water together with the remaining water; and a main-wash water drainage step for draining the wash water together with the remaining water; wherein the pre-steam water supply step comprises: a first water supply step in which wash water is supplied to the pump so as to wash the sump and the pump; and a first drainage step in which the supplied wash water is drained. a sump; a pump for supplying water stored in the sump to an injection arm (711, 713, 715); a pump heater provided in the pump and for heating the water; the method comprising: a main-washing cycle in which one or more washing objects which are held in a tub are washed; a rinsing cycle in which the washing objects washed in the main-washing cycle are rinsed by injecting wash water; and a drying cycle in which the washing objects rinsed in the rinsing cycle are dried, wherein the main-washing cycle comprises, a pre-steam water supply step in which water is supplied to the sump so as to supply steam to the tub; a pre-steam supply step in which the supplied water is heated to generate steam by operating the pump heater and supplying the steam to the tub; a main-wash water supply step in which wash water for washing is supplied to the sump, without draining remaining water supplied in the pre-steam water supply step; a main-washing step in which the washing objects are washed by circulating the supplied wash water together with the remaining water; and a main-wash water drainage step for draining the wash water together with the remaining water; wherein the pre-steam water supply step comprises: a first water supply step in which wash water is supplied to the pump so as to wash the sump and the pump; and a first drainage step in which the supplied wash water is drained. a main-washing cycle in which one or more washing objects which are held in a tub are washed; a rinsing cycle in which the washing objects washed in the main-washing cycle are rinsed by injecting wash water; and a drying cycle in which the washing objects rinsed in the rinsing cycle are dried, wherein the main-washing cycle comprises, a pre-steam water supply step in which water is supplied to the sump so as to supply steam to the tub; a pre-steam supply step in which the supplied water is heated to generate steam by operating the pump heater and supplying the steam to the tub; a main-wash water supply step in which wash water for washing is supplied to the sump, without draining remaining water supplied in the pre-steam water supply step; a main-washing step in which the washing objects are washed by circulating the supplied wash water together with the remaining water; and a main-wash water drainage step for draining the wash water together with the remaining water; a pre-steam water supply step in which water is supplied to the sump so as to supply steam to the tub; a pre-steam supply step in which the supplied water is heated to generate steam by operating the pump heater and supplying the steam to the tub; a main-wash water supply step in which wash water for washing is supplied to the sump, without draining remaining water supplied in the pre-steam water supply step; a main-washing step in which the washing objects are washed by circulating the supplied wash water together with the remaining water; and a main-wash water drainage step for draining the wash water together with the remaining water; wherein the pre-steam water supply step comprises: a first water supply step in which wash water is supplied to the pump so as to wash the sump and the pump; and a first drainage step in which the supplied wash water is drained. a first water supply step in which wash water is supplied to the pump so as to wash the sump and the pump; and a first drainage step in which the supplied wash water is drained.