A laundry treating apparatus comprising: a cabinet having a detergent opening defined therein; a tub installed inside the cabinet; a drum rotatably installed inside the tub; and a storage unit for storing detergent therein, wherein the storage unit includes: a storage frame entered into the cabinet through the detergent opening; a detergent reservoir seated in the storage frame and storing the detergent therein; and an auxiliary detergent container disposed adjacent to the detergent reservoir in the storage frame, and including a front wall, a side wall, and an open top face and a detergent storage space, wherein the detergent reservoir includes a casing having an open top face and storing the detergent therein, and a cap member detachably coupled to the top face of the casing, characterized in that the detergent reservoir is disposed to surround the front portion and the side portion of the auxiliary detergent container and in that the cap member includes a flange portion protruding toward the open top face of the auxiliary detergent container and extended along the front wall and the side wall of the auxiliary detergent container, and wherein a portion of the flange portion forms a gripping portion positioned on the open top face of the auxiliary detergent container. a cabinet having a detergent opening defined therein; a tub installed inside the cabinet; a drum rotatably installed inside the tub; and a storage unit for storing detergent therein, wherein the storage unit includes: a storage frame entered into the cabinet through the detergent opening; a detergent reservoir seated in the storage frame and storing the detergent therein; and an auxiliary detergent container disposed adjacent to the detergent reservoir in the storage frame, and including a front wall, a side wall, and an open top face and a detergent storage space, wherein the detergent reservoir includes a casing having an open top face and storing the detergent therein, and a cap member detachably coupled to the top face of the casing, characterized in that the detergent reservoir is disposed to surround the front portion and the side portion of the auxiliary detergent container and in that the cap member includes a flange portion protruding toward the open top face of the auxiliary detergent container and extended along the front wall and the side wall of the auxiliary detergent container, and wherein a portion of the flange portion forms a gripping portion positioned on the open top face of the auxiliary detergent container. a storage frame entered into the cabinet through the detergent opening; a detergent reservoir seated in the storage frame and storing the detergent therein; and an auxiliary detergent container disposed adjacent to the detergent reservoir in the storage frame, and including a front wall, a side wall, and an open top face and a detergent storage space, wherein the detergent reservoir includes a casing having an open top face and storing the detergent therein, and a cap member detachably coupled to the top face of the casing, characterized in that the detergent reservoir is disposed to surround the front portion and the side portion of the auxiliary detergent container and in that the cap member includes a flange portion protruding toward the open top face of the auxiliary detergent container and extended along the front wall and the side wall of the auxiliary detergent container, and wherein a portion of the flange portion forms a gripping portion positioned on the open top face of the auxiliary detergent container.