A refrigerator and a manufacturing method thereof including processes of separately manufacturing partitions dividing a storage space into a plurality of storage chambers from a main body including an inner casing and an outer casing, coupling the partitions to an inner surface of the inner casing, filling a space between the inner casing and the partitions with an insulator, and filling the partitions with the insulator by filling a space between the inner casing and the outer casing with the insulator. Since the insulator uniformly fills the partitions dividing the storage space into the plurality of storage chambers, the partitions may possess improved insulating qualities.