A refrigerator comprising: a body ; a storage compartment defined in the body ; a door to open or close an open front of the storage compartment ; a storage box having an inner space to store food; and a shelf having a support structure to support food thereon, and protrusion-receiving shelf portions respectively extending along edges of both sides of the support structure and protruding from the support structure , wherein the storage box has slide protrusions respectively formed on both outer side-faces of the storage box at a lower portion thereof, and each of the protrusion-receiving shelf portions has a slide groove to receive the corresponding slide protrusion of the storage box , so that the storage box is able to be slidably mounted/dismounted on/from the protrusion-receiving shelf portions of the shelf , and wherein, when the storage box is mounted on the protrusion-receiving shelf portions of the shelf , food can be put in the inner space of the storage box , whereas when the storage box is dismounted from the frames of the shelf , food can be put on the support structure of the shelf , characterized in that each of the slide protrusions of the storage box comprises a first inclined portion to allow the storage box to move downward as the storage box moves toward a retracted position in the storage compartment , a second inclined portion to allow the storage box to move downward as the storage box moves toward an extended position from the storage compartment , and a balance point separating the first inclined portion and the second inclined portion , the balance point being located at a position nearer a front of the storage box than a rear of the storage box , and the first inclined portion inclines downward from a front side of the storage box to a rear side thereof, while the second inclined portion inclines upward from a front side of the storage box to a rear side thereof. a body ; a storage compartment defined in the body ; a door to open or close an open front of the storage compartment ; a storage box having an inner space to store food; and a shelf having a support structure to support food thereon, and protrusion-receiving shelf portions respectively extending along edges of both sides of the support structure and protruding from the support structure , wherein the storage box has slide protrusions respectively formed on both outer side-faces of the storage box at a lower portion thereof, and each of the protrusion-receiving shelf portions has a slide groove to receive the corresponding slide protrusion of the storage box , so that the storage box is able to be slidably mounted/dismounted on/from the protrusion-receiving shelf portions of the shelf , and wherein, when the storage box is mounted on the protrusion-receiving shelf portions of the shelf , food can be put in the inner space of the storage box , whereas when the storage box is dismounted from the frames of the shelf , food can be put on the support structure of the shelf , characterized in that each of the slide protrusions of the storage box comprises a first inclined portion to allow the storage box to move downward as the storage box moves toward a retracted position in the storage compartment , a second inclined portion to allow the storage box to move downward as the storage box moves toward an extended position from the storage compartment , and a balance point separating the first inclined portion and the second inclined portion , the balance point being located at a position nearer a front of the storage box than a rear of the storage box , and the first inclined portion inclines downward from a front side of the storage box to a rear side thereof, while the second inclined portion inclines upward from a front side of the storage box to a rear side thereof. <EOS>