A laundry treating apparatus, which can perform a laundry drying function, includes a tub in which washing water is accommodated, a drum rotatably installed in the tub, a duct installed on the tub and provided with an air-intake port and an air-inflow port for a flow of air, a blower fan installed in the duct to form the flow of air between the air-intake port and the air-inflow port, a heat exchanger installed in the duct so as to be supplied with cooling water and configured to perform heat exchange so as to cool the air transferred along an inside of the duct, and a heater installed in the duct to heat the air transferred along the inside of the duct.