A washing machine and an operating method thereof are disclosed. A washing machine according to an embodiment of the present invention comprises: a washing tub; a touch screen for outputting a graphical object corresponding to a washing-related function which can be performed by the washing tub; a detergent supplying unit which is formed to receive a laundry detergent in an inner space thereof and supply the received laundry detergent to the washing tub through a supply fluid path; and a control unit which detects a load and a contamination level of laundry in response to input of a washing start command and determines an input quantity of the laundry detergent received in the detergent supplying unit on the basis of the detected load and contamination level. In addition, the control unit displays a graphical object related to the determined laundry detergent input quantity on the touch screen.