Abstract: A refrigerator includes a main body having a storage chamber; a first storage unit formed in the storage chamber, left and right side walls of the first storage unit having first roller supporting surfaces; and a second storage unit having first roller members mounted to a front region of the second storage unit on left and right sides thereof, the first roller members being seated on the first roller supporting surfaces of the first storage unit, a protrusion extending downwardly from a bottom surface of the second storage unit, and second roller members provided on both sides of the second storage unit to move along guide surfaces provided on an interior of the storage chamber. A lateral surface of the protrusion is configured to extend into and contact an interior surface of the first storage unit to prevent the first roller members from laterally leaving the first roller supporting surfaces.