Provided is a washing machine having a detergent supply device in which water supplied to the detergent supply device is evenly distributed in a detergent case so that detergent remaining in the detergent case is washed out completely. The detergent supply device includes a housing having an opening, a detergent case coupled to be movable through the opening and provided with a detergent accommodating part in which a detergent is accommodated, and a water supply unit coupled to the housing and configured to guide water to the detergent case, wherein the water supply unit includes: a first water supply frame provided with a first water supply channel that guides water to a first area corresponding to the detergent accommodating part; and a second water supply frame provided with a second water supply channel that guides water to a second area having at least a portion located outside a circumference of the first area.