The present invention relates to an automatic atomizer. Conventional unmanned automatic sprayers use an automatic sprayer that uses a large number of components and an increase in manufacturing cost due to a complicated configuration. As a result, malfunctions such as clogging of a nozzle spraying a medicine, or a failure of some parts due to excessive pressure And thus waste time, effort, and cost in spraying the medicines. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an automatic atomizer capable of preventing a nozzle from being clogged during operation of the atomizer and preventing the generation of excessive pressure in a high-pressure air generating portion to more effectively spray the agent. In order to achieve the above object, the present invention provides an automatic atomizer including a high-pressure air generator, an injection nozzle, and a chemical mixing tank, comprising: an air distributor for distributing air generated in the high-pressure air generator； An automatic valve that selectively supplies high-pressure air sent from the air distributor to either the injection nozzle or the second branch in accordance with a control signal； A first branch for supplying air from the air distributor and the automatic valve to the injection nozzle； A second branch pipe for supplying the air supplied from the automatic valve to the chemical mixing tank and the injection nozzle； A filter installed at the tip of the medicine supply passage toward the medicine mixing tank； And a control unit for controlling the operation of the high-pressure air generating unit and the automatic valve. According to the present invention, high-pressure air is sprayed toward the injection nozzle and the chemical mixing tank through the automatic valve immediately before the spraying of the medicine by the program of the control unit to clean the spray nozzle, the drug supply passage and the residue attached to the filter A blowing fan
