Method of manufacturing flake aluminum oxide using microwave

The present disclosure suggests a method of manufacturing flake aluminum oxide using a microwave including: performing a pre-treatment on a starting material by grinding the starting material such as alumina hydrate, aluminum salt or the like and classifying particles with an appropriate size; manufacturing transition alumina by performing a heat treatment by means of heating the pre-treated starting material; mixing the transition alumina with molten salt and an additive and then dispersing and grinding the mixed compounds; melting and synthesizing flake aluminum oxide by heating the dispersed and grinded mixture with a microwave as a heating source; separating the molten salt and the additive from the synthesized aluminum oxide; and performing a post-treatment on the flake aluminum oxide by removing a foreign substance such as an additive residue stuck to a surface of a crystal particle of the separated flake aluminum oxide.