A laundry treating apparatus comprising: a tub for providing a space where water is stored; a drum rotatably provided inside the tub, for storing laundry therein; a cover provided with a detergent inlet; a storage body arranged below the cover, providing a space where a detergent is stored; a barrier provided in the storage body, for partitioning the inside of the storage body into a first space where the detergent entering through the detergent inlet is stored, and a second space detached from the first space; a storage unit water supply inlet allowing water to enter the first space; a first body through hole provided to pass through a bottom of the storage body, communicating the first space with the tub; a first discharge pipe protruded toward the cover from the first body through hole; a second discharge pipe provided on a bottom of the storage body, communicating the second space with the tub; a siphon formation pipe provided to surround the first discharge pipe, moving a liquid inside the first space to the first body through hole if a water level inside the first space is higher than a height of the first discharge pipe; and a space communication unit for moving the liquid inside the first space to the second space if the liquid is not discharged to the outside of the first space through the first body through hole; characterised by the laundry treating apparatus further comprising: a detergent inlet pipe provided to pass through the tub; a connection pipe for connecting the detergent inlet pipe with the second discharge pipe; a first backward flow preventer provided in the second discharge pipe to prevent the water inside the tub from entering the storage body; and a second backward flow preventer provided in the detergent inlet pipe to prevent the water inside the tub from entering the storage body, wherein the first body through hole is provided to discharge the liquid inside the first space to the second discharge pipe. a tub for providing a space where water is stored; a drum rotatably provided inside the tub, for storing laundry therein; a cover provided with a detergent inlet; a storage body arranged below the cover, providing a space where a detergent is stored; a barrier provided in the storage body, for partitioning the inside of the storage body into a first space where the detergent entering through the detergent inlet is stored, and a second space detached from the first space; a storage unit water supply inlet allowing water to enter the first space; a first body through hole provided to pass through a bottom of the storage body, communicating the first space with the tub; a first discharge pipe protruded toward the cover from the first body through hole; a second discharge pipe provided on a bottom of the storage body, communicating the second space with the tub; a siphon formation pipe provided to surround the first discharge pipe, moving a liquid inside the first space to the first body through hole if a water level inside the first space is higher than a height of the first discharge pipe; and a space communication unit for moving the liquid inside the first space to the second space if the liquid is not discharged to the outside of the first space through the first body through hole; characterised by the laundry treating apparatus further comprising: a detergent inlet pipe provided to pass through the tub; a connection pipe for connecting the detergent inlet pipe with the second discharge pipe; a first backward flow preventer provided in the second discharge pipe to prevent the water inside the tub from entering the storage body; and a second backward flow preventer provided in the detergent inlet pipe to prevent the water inside the tub from entering the storage body, wherein the first body through hole is provided to discharge the liquid inside the first space to the second discharge pipe. a detergent inlet pipe provided to pass through the tub; a connection pipe for connecting the detergent inlet pipe with the second discharge pipe; a first backward flow preventer provided in the second discharge pipe to prevent the water inside the tub from entering the storage body; and a second backward flow preventer provided in the detergent inlet pipe to prevent the water inside the tub from entering the storage body, wherein the first body through hole is provided to discharge the liquid inside the first space to the second discharge pipe.