A refrigerator including an inner case, an outer case, and a vacuum space provided between the inner case and the outer case to insulate the inner case from the outer case. The inner case defines an exterior appearance of a storage space, with a communication hole formed therein. The outer case is spaced apart a predetermined distance from the inner case, and a communication is formed at a position corresponding to the communication hole of the inner case. A connection pipe passes through the vacuum space to connect the communication hole of the inner case and the communication hole of the outer case with each other.