A clothes treating apparatus comprising: a case in which a treatment chamber for holding clothes is provided; a steam unit configured for supplying steam to the treatment chamber; a storage tank configured for storing water to be supplied to the steam unit; a valve unit disposed in a flow channel connecting the storage tank and the steam unit; a water supply pump configured for generating driving power to transmit water stored in the storage tank to the steam unit; and a control unit configured for controlling the steam unit and the water supply pump, wherein the valve unit is configured to open or close the flow channel by at least one of water and steam flowing in the flow channel, wherein the valve unit is a mechanical valve operating independently from the control unit, characterized in that: the valve unit includes a main body having a hollow portion therein, and a rod member provided to be movable within the main body, wherein the valve unit is configured to adopt a first state in which the rod member has moved toward the steam unit within the hollow portion to open the hollow portion to allow water supplied from the storage tank to flow, and a second state in which the rod member has moved toward the storage tank within the hollow portion to close the hollow portion to prevent a flow of steam generated by the steam unit towards the storage tank, wherein a portion of a hollow channel in which the valve unit is provided is formed in a substantially vertical direction, wherein the valve unit is configured to adopt the first state in which the rod member has moved downwards within the hollow portion to open the hollow portion to allow water supplied from the storage tank to flow when the steam unit is stopped, and the second state in which the rod member has moved upwards within the hollow portion to close the hollow portion to prevent a flow of steam generated by the steam unit towards the storage tank when the steam unit operates, and wherein the rod member is configured to be positioned on a lower side within the hollow portion by gravity when both the water supply pump and the steam unit are stopped. a case in which a treatment chamber for holding clothes is provided; a steam unit configured for supplying steam to the treatment chamber; a storage tank configured for storing water to be supplied to the steam unit; a valve unit disposed in a flow channel connecting the storage tank and the steam unit; a water supply pump configured for generating driving power to transmit water stored in the storage tank to the steam unit; and a control unit configured for controlling the steam unit and the water supply pump, wherein the valve unit is configured to open or close the flow channel by at least one of water and steam flowing in the flow channel, wherein the valve unit is a mechanical valve operating independently from the control unit, characterized in that: the valve unit includes a main body having a hollow portion therein, and a rod member provided to be movable within the main body, wherein the valve unit is configured to adopt a first state in which the rod member has moved toward the steam unit within the hollow portion to open the hollow portion to allow water supplied from the storage tank to flow, and a second state in which the rod member has moved toward the storage tank within the hollow portion to close the hollow portion to prevent a flow of steam generated by the steam unit towards the storage tank, the valve unit includes a main body having a hollow portion therein, and a rod member provided to be movable within the main body, wherein the valve unit is configured to adopt a first state in which the rod member has moved toward the steam unit within the hollow portion to open the hollow portion to allow water supplied from the storage tank to flow, and a second state in which the rod member has moved toward the storage tank within the hollow portion to close the hollow portion to prevent a flow of steam generated by the steam unit towards the storage tank, wherein a portion of a hollow channel in which the valve unit is provided is formed in a substantially vertical direction, wherein the valve unit is configured to adopt the first state in which the rod member has moved downwards within the hollow portion to open the hollow portion to allow water supplied from the storage tank to flow when the steam unit is stopped, and the second state in which the rod member has moved upwards within the hollow portion to close the hollow portion to prevent a flow of steam generated by the steam unit towards the storage tank when the steam unit operates, and wherein the rod member is configured to be positioned on a lower side within the hollow portion by gravity when both the water supply pump and the steam unit are stopped.