A refrigerator comprising: a main body comprising a first cooling space; a door that selectively seals the first cooling space of the main body; a first heat pump module built in the main body and configured to cool the first cooling space; an independent refrigerator that is detachably disposed in the first cooling space sealed by the door and forms an insulating space independent of the first cooling space; a second heat pump module built in the independent refrigerator to cool a second cooling space of the independent refrigerator; a main body power supply part that is built in the main body and supplies power; and an independent power supply part built in the independent refrigerator, wherein the independent refrigerator comprises: an outer housing forming an external shape of the independent refrigerator; an inner housing forming the second cooling space of the independent refrigerator; and a storage compartment that enters and exits the inner housing, and wherein the second heat pump module is disposed in a space between the outer housing and the inner housing, characterized in that the independent refrigerator further comprises a sliding door that is disposed on a surface of the storage compartment and seals the second cooling space together with the inner housing, wherein the sliding door comprises a control panel configured to control the independent refrigerator and display information of the independent refrigerator. a main body comprising a first cooling space; a door that selectively seals the first cooling space of the main body; a first heat pump module built in the main body and configured to cool the first cooling space; an independent refrigerator that is detachably disposed in the first cooling space sealed by the door and forms an insulating space independent of the first cooling space; a second heat pump module built in the independent refrigerator to cool a second cooling space of the independent refrigerator; a main body power supply part that is built in the main body and supplies power; and an independent power supply part built in the independent refrigerator, wherein the independent refrigerator comprises: an outer housing forming an external shape of the independent refrigerator; an inner housing forming the second cooling space of the independent refrigerator; and a storage compartment that enters and exits the inner housing, and wherein the second heat pump module is disposed in a space between the outer housing and the inner housing, characterized in that the independent refrigerator further comprises a sliding door that is disposed on a surface of the storage compartment and seals the second cooling space together with the inner housing, wherein the sliding door comprises a control panel configured to control the independent refrigerator and display information of the independent refrigerator. an outer housing forming an external shape of the independent refrigerator; an inner housing forming the second cooling space of the independent refrigerator; and a storage compartment that enters and exits the inner housing, and wherein the second heat pump module is disposed in a space between the outer housing and the inner housing, characterized in that the independent refrigerator further comprises a sliding door that is disposed on a surface of the storage compartment and seals the second cooling space together with the inner housing, wherein the sliding door comprises a control panel configured to control the independent refrigerator and display information of the independent refrigerator.