To economically and efficiently produce a polyurethane compound for obtaining coating materials and adhesives having excellent properties, such as weatherability and corrosion resistance, without using phosgene.

A formamide compound and dimethyl carbonate, or methyl formate, an amine compound and dimethyl carbonate are reacted in the presence of an alkali catalyst to give a urethane compound. This urethane compound is thermally decomposed at 150-350°C without using any catalyst to give an isocyanate compound, from which a polyurethane compound is produced.