Embodiments of the present disclosure relate to an outdoor unit of an air conditioner configured to cool a heating unit by making contact with the heating unit, a cooling unit applied thereto, and a method for manufacturing the cooling unit. An outdoor unit of an air conditioner comprises a compressor configured to compress refrigerant; a condenser configured to condense the refrigerant discharged from the compressor; a control box provided with an electronic component configured to control an outdoor unit of an air conditioner; and a cooling unit configured to cool a heating unit by making contact with the heating unit of the electronic component, wherein the cooling unit comprises a heat radiating member having one side thereof make contact with the heating unit; and a refrigerant pipe extended by penetrating through the heat radiating member and in which refrigerant is moved.