Storage box assembly and refrigerator including the same

A storage box assembly, comprising:

• a housing including a base plate and first and second upright
• sidewalls at first and second side edges of the base plate, each upright sidewall having a front groove and a rear groove on a top surface;
• a movable storage box accommodated in the housing, the storage box having first and second side panels, a bottom panel and an open top, each of the first and second side panels having an upper end slanted downward from a front end toward a rear end of the movable storage box such that the height of the front end is greater than the rear end, and having front and rear lifters protruding from the upper end;
• and
• a cover configured to cover the open top when the movable storage box is in a closed position within the housing, the cover including:
• side surfaces having bottom ends which are slanted such that a front end of each side surface has a lower height than a rear end,
• front and rear protrusions which protrude from the each side surface and configured to seated in the front and rear grooves, respectively,
• first and second flanges at the bottom ends of both side surfaces, and
• front and rear lift recesses on both first and second flanges, the front and rear lift recesses facing the front and rear protrusions of the storage box such that the front and rear protrusions are seated in the front and rear lift recesses when the storage box is in the closed position.