A water treatment apparatus is disclosed. The water treatment apparatus, according to one embodiment of the present invention, may comprise: a filter unit comprising a reverse osmosis filter for supplying purified water filtered from raw water, and residential water which could not be filtered from raw water; a storage unit connected to the filter unit and comprising a storage member in which purified water is stored, then discharged, and a housing within which the storage member is provided, and through which residential water inflows and outflows; and a flow path changing valve connected to the filter unit and the storage unit, and which allows residential water to outflow from the housing as purified water is stored in the storage member, or allows purified water to be discharged from the storage member as residential water inflows into the housing.