Method for controlling laundry treating apparatus

A method for controlling a laundry treating apparatus including a drum rotatably disposed inside a tub and constructed to store laundry therein, a water supply flow channel constructed to guide water to the tub, a supplier constructed to store liquid therein, a transferer constructed to move the liquid stored in the supplier to the water supply flow channel, and a sensor including two electrodes fixed at spaced locations inside the water supply flow channel, the method comprising:

• a mode selection step of selecting a washing mode;
• a washing step of discharging the liquid inside the supplier via the transferer into the water supply flow channel to wash the water supply flow channel and the transferer when the washing mode is selected;
• and
• a sensing step of supplying a preset voltage to a circuit including the two electrodes and measuring a current value between the two electrodes to determine a type of the liquid discharged from the supplier, wherein the sensing step is performed during execution of the washing step.