A refrigerator is provided which includes an ice maker, a dispenser and the other related components installed to a refrigerator door that opens and closes a storage space of a main body of the refrigerator, the walls of which are formed of insulating layers. A water supply tube is provided in the door to pass through a lower hinge and extend through the door so that water can be supplied to a filter in a filter chamber defined within the door. The water purified in the filter is supplied through a valve to the ice maker and dispenser. The filter chamber is configured to be opened and closed by a service door so that a user can more easily exchange the filter. The service door is provided in front of the door. Since the ice maker, the dispenser and the related components are integrated within the door, the storage space defined by the main body of the refrigerator can be further increased. In addition, a function of the refrigerator can also be improved by merely exchanging the door rather than the whole refrigerator.