An object of the present invention is providing a method for producing formic acid under mild reaction conditions and by a simple procedure. As a means for achieving the object, the method for producing formic acid of the present invention is characterized by a reaction between carbon dioxide and hydrogen in the presence of an ionic liquid. According to the present invention, it is possible to generate formic acid effectively, because the method does not require that carbon dioxide be brought into a supercritical state and because no basic substances are required to be added to the reaction system.