Abstract: A water purifier includes: a purified water tank storing purified water; a hot water tank connected to the purified water tank to receive the purified water from the purified water tank and including a heater heating the received purified water; a manipulation unit through which an extraction amount of hot water is inputted; and a control unit performing a control to supply the purified water of the purified water tank to the hot water tank by the extraction amount of hot water, when the extraction amount of hot water is inputted to the manipulation unit, and operating the heater to heat the water of the hot water tank. According to the present invention, the power consumption of the water purifier decreases in comparison with a conventional water purifier. Furthermore, it is possible to provide an accurate amount of hot water to a user without using a water level sensor.