A process for production of a functional film comprises a coating liquid preparation step (12) of preparing a coating liquid; an application step (14) of applying a monolayer of the prepared coating liquid onto a substrate (18); and a drying step (16) of drying the applied coated layer. At the coating liquid preparation step (12), a plurality of solute materials are contained in at least one solvent; and when D11 is a main diffusion coefficient of a solute material A having functionality of the plurality of solute materials A and B and D22 is a main diffusion coefficient of the other solute material B, the other solute material B is selected so that an inequality A D11