There is disclosed that a MOx nanostructure manufacturing apparatus and a manufacturing method thereof can not only supply a reaction gas more effectively to the surface of a molten metal with ease by injecting a carrier gas to the surface of the molten metal above a graphite crucible as well as bringing the reaction gas in the lower side of the graphite crucible, but also maximize volatilization rates through an inflow of the reaction gas from the lower portion toward the upper of the graphite crucible.