A washing machine that performs a washing course by heating wash water and a control method thereof are provided. The method includes supplying wash water up to a wash water level for generation of steam such that a portion of laundry received in an inner tub is saturated by the wash water. The wash water level may be above a bottom surface of the inner tub and below a wash water level for main washing. The method then includes heating the wash water to a first set temperature and driving a washing heater to generate steam from the wash water, and supplying the generated steam to the inner tub, and then supplying the wash water up to the wash water level for main washing, and driving the washing heater again to heat the wash water to a second set temperature, the second set temperature being lower than the first set temperature.