A washing machine comprising: a body ; a tub provided inside of the body to store water; a detergent supply unit disposed adjacent to the tub to supply detergent to the tub during an operating mode for washing laundry and to receive water during a cleaning mode; and a controller configured to allow a cleaning of the detergent supply unit to be performed by controlling a flow of water of the detergent supply unit and the tub during the cleaning mode of the detergent supply unit ; wherein the detergent supply unit comprises a detergent storage having a housing fixedly installed in the body ; a detergent container placed inside of the housing to store the detergent and configured to be withdrawable to the outside and provided with an opening; and a cover configured to open and close the opening; and a detergent discharge unit configured to discharge the detergent of the detergent storage based on a command of the controller , a door configured to open and close an inlet formed in the tub ; characterized in that the detergent supply unit is disposed in a lower portion of the front side of the body , and the washing machine further comprises a first detector configured to detect whether the door is closed or not; and a second detector configured to detect whether the detergent container is separated or not, wherein, when controlling cleaning the detergent supply unit , the controller determines whether the door is closed, based on a detection signal of the first detector and determines whether the detergent container is separated, based on a detection signal of the second detector , and when it is determined that the door is closed and the detergent container is separated from the housing , the controller controls cleaning of the detergent supply unit . a body ; a tub provided inside of the body to store water; a detergent supply unit disposed adjacent to the tub to supply detergent to the tub during an operating mode for washing laundry and to receive water during a cleaning mode; and a controller configured to allow a cleaning of the detergent supply unit to be performed by controlling a flow of water of the detergent supply unit and the tub during the cleaning mode of the detergent supply unit ; wherein the detergent supply unit comprises a detergent storage having a housing fixedly installed in the body ; a detergent container placed inside of the housing to store the detergent and configured to be withdrawable to the outside and provided with an opening; and a cover configured to open and close the opening; and a detergent discharge unit configured to discharge the detergent of the detergent storage based on a command of the controller , a door configured to open and close an inlet formed in the tub ; characterized in that the detergent supply unit is disposed in a lower portion of the front side of the body , and the washing machine further comprises a first detector configured to detect whether the door is closed or not; and a second detector configured to detect whether the detergent container is separated or not, wherein, when controlling cleaning the detergent supply unit , the controller determines whether the door is closed, based on a detection signal of the first detector and determines whether the detergent container is separated, based on a detection signal of the second detector , and when it is determined that the door is closed and the detergent container is separated from the housing , the controller controls cleaning of the detergent supply unit . <EOS>