Disclosed is a dishwasher that sprays washing water and steam to wash dishes or cooking appliances. The dishwasher according to the present invention includes: a tub which receives a target of washing; a sump which is disposed at a bottom of the tub to store washing water; a spray arm which sprays the washing water stored in the sump into the tub; a heater which generates heat by heating washing water in a circulation passage connecting the sump and the spray arm; and a steam passage which is connected to the steam nozzle, and in which the steam generated by the heater flows. Accordingly, the steam generated in the circulation passage may be supplied smoothly.