PROBLEM TO BE SOLVED: To provide a method of simply and efficiently producing metal oxide particles with spherical shape, the particles comprising a general metal oxide, by using a flame fusion method that can be implemented at low cost and is applicable to industrial mass production.SOLUTION: The method of producing the metal oxide particle with spherical shape includes a step of heating one or more nonvaporizable metal chelate powder in a thermal fluid to pyrolyze an organic component in the powder for removal and to oxidize a metal component.