Manufacturing method of the isocyanate compound

In making the isocyanate compound, to prevent the clogging of the reaction tube. Only by thermal decomposition, at a high reaction rate and in high yields, producing an isocyanate compound. Method for producing an isocyanate compound of the present invention includes the step of supplying a carbamate compound with a carrier gas into the hollow space free of solid catalyst and / or filler, a step of thermally decomposing the carbamate compound in said hollow space, the It has. Wherein the volume of the hollow space, wherein the carbamate compound and divided by the total supply amount per unit time of the carrier gas (N) is 0.001 to 2.