A drum type washing machine includes a rotary drum having an approximately horizontal or slanted rotational axis; an outer tub for accommodating the rotary drum therein; a driving motor for rotating the rotary drum; a detergent case for accommodating detergent therein; a first water supply unit for supplying water into the outer tub via the detergent case; a second water supply unit for supplying water into the rotary drum through a front opening thereof; and a controller for controlling operations of the driving motor and the first and the second water supply unit to execute a washing process during which water is supplied first up to a first water level, and the rotary drum is rotated at a first rotational speed for a time period, and then water is supplied up to a second water level, the first water level being lower than the second water level.