The present invention relates to an air supply apparatus for controlling a temperature of a living fish aquarium, the apparatus comprising: a case having a space therein and opened at an upper part thereof； And the other end is connected to a compressor for sucking and discharging the outside air, and the other end is connected to one end of the circulation conduit An air cooler connected to the compressor for cooling the compressed air supplied from the compressor and discharging the compressed air to one end of the circulation channel； an end of the air cooler connected to an outlet of the circulation channel； A distribution hose for transferring cooled air flowing through the distribution channel to the air supply unit； A switching valve that is disposed between the distribution hoses and determines whether the air discharged through the discharge port is supplied to the distribution hose； And one end of which is connected to the other end of the circulation hose to discharge the cooled air supplied from the circulation hose to the aquarium to supply oxygen to the aquarium water And an air supplier for cooling the temperature of the water. Air cooled by air cooler and thermoelectric element is supplied to the aquarium to prevent the water temperature from rising. It is very convenient to install the device because it has very simple structure and it consumes a small amount of electric energy It is possible to greatly reduce the production cost of the apparatus due to the simple structure and to enhance the versatility of the apparatus. In addition, the air to be supplied to the aquarium is first cooled through the air cooler, the circulation channel through which the cooled air flows is secondarily cooled through the cooling means, and the cooled air is uniformly supplied to the aquarium through the air feeder In addition to being able to maintain the temperature of the whole aquarium uniformly, it can induce the stable survival of fish. In addition, the controll
