To provide a refrigerator and chamber increase boxes for forming a vegetable chamber, a freezing chamber, and the like in the refrigerator as separate refrigerators according to purposes, combining only the required refrigerators, and mounting the chamber increase boxes usable in combination to increase capacity if necessary or as storage boxes.

The vegetable chamber, the freezing chamber, and the like in the refrigerator are formed as the separate refrigerators 1 according to purposes. The refrigerators 1 as well as the chamber 2 for increasing boxes 2 with no cooling function are provided with air intake ports 3 and blow out ports 4 at the top, bottom, left and right and at the back. The refrigerators 1 adjacent to each other, or the refrigerator 1 and the chamber increase box 2, are connected and fixed to each other by fastening internal screws 6 provided inside the intake ports 3 and blow out ports 4 to pipes formed with external screws 7 for connecting and fixing to allow cold air to flow, thus increasing the capacity of the refrigerator. Further, the refrigerators 1 and the chamber increase boxes 2 can be integrated.