A method for cleaning a water purifier comprising: a filtering unit; a water tank unit for storing purified water having passed through the filtering unit; and a discharging unit for discharging out the purified water stored in the water tank unit, the method comprises: a cleaning water supplying step of supplying cleaning water in which a cleaning agent is dissolved to the water tank unit; a cleaning water discharging step of discharging the cleaning water when a predetermined time has lapsed; a rinsing water supplying step of supplying rinsing water to the water tank unit when the cleaning water discharging step has been completed; and a rinsing water discharging step of discharging the rinsing water when a predetermined time has lapsed. In the method, cleaning and rinsing processes for a water purifier are automatically executed by a series of consecutive processes. Accordingly, a user can directly clean the water purifier if necessary without requiring a Codi's visit.