A method for protecting a washing machine from freezing including a tub to contain wash water, and a control unit to control supply and drainage of water, characterized in that the method comprises: detecting, by a laundry weight detection unit, a weight of laundry items after a washing process, when a freeze protection course is selected; determining, by the control unit, whether or not laundry items exist based on the detecting result; determining, by the control unit, whether a freeze protection operation condition is satisfied, when no laundry items exist; supplying water from a water supply device and draining or discharging water using a drain device when the freeze protection operation condition is satisfied; and determining again whether the freeze protection operation condition is satisfied a preset standby time after supplying the water and draining or discharging the water, wherein determining whether the freeze protection operation condition is satisfied comprises: determining, by the control unit, whether a preset operation time has arrived; comparing, by the control unit, the number of freeze protection operations to a preset number of repetitions after the operation time has arrived; and determining, by the control unit, that the freeze protection operation condition is satisfied when the number of freeze protection operations does not exceed the preset number of repetitions, wherein the preset operation time is a specific reserved time. detecting, by a laundry weight detection unit, a weight of laundry items after a washing process, when a freeze protection course is selected; determining, by the control unit, whether or not laundry items exist based on the detecting result; determining, by the control unit, whether a freeze protection operation condition is satisfied, when no laundry items exist; supplying water from a water supply device and draining or discharging water using a drain device when the freeze protection operation condition is satisfied; and determining again whether the freeze protection operation condition is satisfied a preset standby time after supplying the water and draining or discharging the water, wherein determining whether the freeze protection operation condition is satisfied comprises: determining, by the control unit, whether a preset operation time has arrived; comparing, by the control unit, the number of freeze protection operations to a preset number of repetitions after the operation time has arrived; and determining, by the control unit, that the freeze protection operation condition is satisfied when the number of freeze protection operations does not exceed the preset number of repetitions, wherein the preset operation time is a specific reserved time. determining, by the control unit, whether a preset operation time has arrived; comparing, by the control unit, the number of freeze protection operations to a preset number of repetitions after the operation time has arrived; and determining, by the control unit, that the freeze protection operation condition is satisfied when the number of freeze protection operations does not exceed the preset number of repetitions, wherein the preset operation time is a specific reserved time.