An object of the present invention is to provide a method of vapor phase catalytic oxidation which is capable of: efficiently removing heat of reaction; preventing the formation of hot spots; and efficiently providing a desired product. The invention provides a method of vapor phase catalytic oxidation of a substance to be oxidized with a gas containing molecular oxygen by means of a multitubular reactor, wherein the method comprises: performing a reaction of vapor phase catalytic oxidation under such conditions that a heat transfer coefficient of the heat medium is 1,000 W/(m.sup.2K) or higher.