A refrigerator having an air processing apparatus comprising: a first cabinet comprising a storage compartment defining a space in which objects for refrigerating or freezing are stored; and a first door for opening and closing the storage compartment; a first cooling unit comprising a first refrigerant pipe defining a circulation path of a refrigerant; a first compressor configured to circulate the refrigerant along the first refrigerant pipe; a first condenser configured to condense the refrigerant by exchanging heat between the refrigerant exhausted from the first compressor and external air of the storage compartment; a first pressure regulator configured to lower the pressure of the refrigerant having passed the first condenser; and a first evaporator configured to vaporize the refrigerant having passed the first pressure regulator by absorbing heat from the internal air of the storage compartment; a second cabinet detachably mounted on one surface of the first cabinet and comprising an inlet hole and an outlet hole; a blower fan provided in the second cabinet and configured to blow the air drawn into the inlet hole toward the outlet hole; a filter unit configured to filter the air drawn into the second cabinet via the inlet hole; a first printed circuit board, PCB, comprising a first control unit implemented to control at least one of the first compressor and the first pressure regulator; a second PCB comprising a second control unit implemented to control the blower fan; a first mounting unit provided in one surface of the first cabinet and defining a predetermined space which accommodates the first PCB in case the second cabinet is detached; the refrigerator being characterized by a second mounting unit provided in one surface of the second cabinet and defining a predetermined space which accommodates both the first PCB and the second PCB in case the second cabinet is mounted. a first cabinet comprising a storage compartment defining a space in which objects for refrigerating or freezing are stored; and a first door for opening and closing the storage compartment; a first cooling unit comprising a first refrigerant pipe defining a circulation path of a refrigerant; a first compressor configured to circulate the refrigerant along the first refrigerant pipe; a first condenser configured to condense the refrigerant by exchanging heat between the refrigerant exhausted from the first compressor and external air of the storage compartment; a first pressure regulator configured to lower the pressure of the refrigerant having passed the first condenser; and a first evaporator configured to vaporize the refrigerant having passed the first pressure regulator by absorbing heat from the internal air of the storage compartment; a second cabinet detachably mounted on one surface of the first cabinet and comprising an inlet hole and an outlet hole; a blower fan provided in the second cabinet and configured to blow the air drawn into the inlet hole toward the outlet hole; a filter unit configured to filter the air drawn into the second cabinet via the inlet hole; a first printed circuit board, PCB, comprising a first control unit implemented to control at least one of the first compressor and the first pressure regulator; a second PCB comprising a second control unit implemented to control the blower fan; a first mounting unit provided in one surface of the first cabinet and defining a predetermined space which accommodates the first PCB in case the second cabinet is detached; the refrigerator being characterized by a second mounting unit provided in one surface of the second cabinet and defining a predetermined space which accommodates both the first PCB and the second PCB in case the second cabinet is mounted.