An air conditioner comprising: an electronic unit comprising a control component for driving a refrigerant cycle; and a cooling tube through which a refrigerant for cooling the electronic unit flows, the cooling tube being coupled to one side of the electronic unit, wherein the electronic unit comprises: an electronic case having a through part (305, 306); an electronic board to which the control component is coupled, the electronic board being disposed within the electronic case; a heat transfer plate disposed to contact the control component, the heat transfer plate being coupled to the electronic case; a heat-sink plate (331, 333) to which the cooling tube is coupled, the heat-sink plate (331, 333) contacting the heat transfer plate through the through part (305, 306); fixing guides spacing the electronic board apart from the heat transfer plate, being disposed on the same side of the heat transfer plate but spaced from each other at opposite ends; characterised by first coupling members configured to couple the fixing guides and the heat transfer plate to the inner surface of the electronic case, wherein the first coupling members pass through the respective fixing guide and the heat transfer plate so as to couple them to the electronic case. an electronic unit comprising a control component for driving a refrigerant cycle; and a cooling tube through which a refrigerant for cooling the electronic unit flows, the cooling tube being coupled to one side of the electronic unit, wherein the electronic unit comprises: an electronic case having a through part (305, 306); an electronic board to which the control component is coupled, the electronic board being disposed within the electronic case; a heat transfer plate disposed to contact the control component, the heat transfer plate being coupled to the electronic case; a heat-sink plate (331, 333) to which the cooling tube is coupled, the heat-sink plate (331, 333) contacting the heat transfer plate through the through part (305, 306); fixing guides spacing the electronic board apart from the heat transfer plate, being disposed on the same side of the heat transfer plate but spaced from each other at opposite ends; characterised by first coupling members configured to couple the fixing guides and the heat transfer plate to the inner surface of the electronic case, wherein the first coupling members pass through the respective fixing guide and the heat transfer plate so as to couple them to the electronic case. an electronic case having a through part (305, 306); an electronic board to which the control component is coupled, the electronic board being disposed within the electronic case; a heat transfer plate disposed to contact the control component, the heat transfer plate being coupled to the electronic case; a heat-sink plate (331, 333) to which the cooling tube is coupled, the heat-sink plate (331, 333) contacting the heat transfer plate through the through part (305, 306); fixing guides spacing the electronic board apart from the heat transfer plate, being disposed on the same side of the heat transfer plate but spaced from each other at opposite ends; characterised by first coupling members configured to couple the fixing guides and the heat transfer plate to the inner surface of the electronic case, wherein the first coupling members pass through the respective fixing guide and the heat transfer plate so as to couple them to the electronic case.