A refrigerator comprising: a main body; a storage compartment (50, 60) provided in the main body; a sliding door to open or close the storage compartment (50, 60); a storage basket which moves together with the door to be drawn into or out of the storage compartment (50, 60); and an auxiliary basket supported by the storage basket and being drawn into and out on an upper portion of the storage basket of the storage chamber, wherein the auxiliary basket includes a roller; wherein the storage basket includes: a roller support surface configured to support the roller so that the roller performs a rolling motion, a front protrusion protruding upward from a front portion of the roller support surface, the front protrusion configured to press against the roller to restrict a forward movement of the roller along the roller support surface when the door is being closed, characterized in that the storage basket further includes: a rear protrusion protruding upward from a rear portion of the roller support surface to restrict a backward movement of the roller along the roller support surface, and an auxiliary protrusion protruding upward from the roller support surface between the front protrusion and the rear protrusion, and being positioned closer to the front protrusion than the rear protrusion, so that when the roller is supported on the roller support surface and disposed between the front protrusion and the auxiliary protrusion, the auxiliary basket is drawn out together with the storage basket by the auxiliary protrusion pressing against the roller as the door is being opened, and the auxiliary basket is drawn in together with the storage basket by the front protrusion pressing against the roller as the door is being closed, and wherein the auxiliary protrusion is formed to have a lower height than the front protrusion to enable the roller to be moved over the auxiliary protrusion. a main body; a storage compartment (50, 60) provided in the main body; a sliding door to open or close the storage compartment (50, 60); a storage basket which moves together with the door to be drawn into or out of the storage compartment (50, 60); and an auxiliary basket supported by the storage basket and being drawn into and out on an upper portion of the storage basket of the storage chamber, wherein the auxiliary basket includes a roller; wherein the storage basket includes: a roller support surface configured to support the roller so that the roller performs a rolling motion, a front protrusion protruding upward from a front portion of the roller support surface, the front protrusion configured to press against the roller to restrict a forward movement of the roller along the roller support surface when the door is being closed, a roller support surface configured to support the roller so that the roller performs a rolling motion, a front protrusion protruding upward from a front portion of the roller support surface, the front protrusion configured to press against the roller to restrict a forward movement of the roller along the roller support surface when the door is being closed, characterized in that the storage basket further includes: a rear protrusion protruding upward from a rear portion of the roller support surface to restrict a backward movement of the roller along the roller support surface, and an auxiliary protrusion protruding upward from the roller support surface between the front protrusion and the rear protrusion, and being positioned closer to the front protrusion than the rear protrusion, so that when the roller is supported on the roller support surface and disposed between the front protrusion and the auxiliary protrusion, the auxiliary basket is drawn out together with the storage basket by the auxiliary protrusion pressing against the roller as the door is being opened, and the auxiliary basket is drawn in together with the storage basket by the front protrusion pressing against the roller as the door is being closed, and wherein the auxiliary protrusion is formed to have a lower height than the front protrusion to enable the roller to be moved over the auxiliary protrusion. a rear protrusion protruding upward from a rear portion of the roller support surface to restrict a backward movement of the roller along the roller support surface, and an auxiliary protrusion protruding upward from the roller support surface between the front protrusion and the rear protrusion, and being positioned closer to the front protrusion than the rear protrusion, so that when the roller is supported on the roller support surface and disposed between the front protrusion and the auxiliary protrusion, the auxiliary basket is drawn out together with the storage basket by the auxiliary protrusion pressing against the roller as the door is being opened, and the auxiliary basket is drawn in together with the storage basket by the front protrusion pressing against the roller as the door is being closed, and wherein the auxiliary protrusion is formed to have a lower height than the front protrusion to enable the roller to be moved over the auxiliary protrusion.