PURPOSE: To provide a dishwasher which can remove well protein contamination attached to tableware.

CONSTITUTION: This washer is equipped with a washing tank 10; a detergent supply means to supply a detergent to washing water; a pump 2 to pressurize washing water; a nozzle 12 to jet washing water to tableware; a heater 7 to heat washing water; a hot water supply pipe 2 to supply hot water to a washing water storing portion; a hot water supply control valve disposed on the hot water supply pipe 2; a washing water temperature sensor 8 to detect the temperature of washing water; and a control portion 1 that receives as input a temperature signal from the sensor 8 and controls the detergent supply means, the pump 2, the heater 7 and the hot water supply control valve. In a detergent washing process to wash jettingly tableware by using washing water supplied with the detergent, control is conducted so that during a predetermined time after the start of the process, the temperature of washing water may be kept at a predetermined temperature at which the coagulation of protein contamination attached to tableware does not occur.