PURPOSE: To produce the titled compound useful as a raw material of pharmaceuticals, agricultural chemicals, etc., in high yield and purity, by reacting a benzoic acid compound with urea in molten state keeping the reaction mixture to a temperature above a specific temperature at least in the latter stage of the reaction.

CONSTITUTION: The objective benzonitrile compound is obtained by reacting a benzoic acid compound with urea in molten state keeping the reaction mixture at a temperature above a specific temperature at least in the latter stage of the reaction. In the former stage of the reaction, the benzoic acid compound is made to react with urea to form mainly a benzamide compound, and when the benzoic acid compound is converted almost completely to the benzamide compound, the reaction mixture is heated at ≥220°C in the latter stage of the reaction to convert the benzamide compound to benzonitrile compound. Since the boiling point of benzonitrile compound is usually 220W260°C, the reaction is carried out while distilling out the produced benzonitrile compound from the reactor together with by-produced water. The equilibrium of the reaction is shifted to the product side, and the product can be separated by this process without thermal degradation.