Mean-field theory(LGD) for ferroelectric films at the nanoscale -- Critical thickness from the mean-field theory (LGD) and from the first principles -- Size effect at the nanoscale -- Polymeric ferroelectric Langmuir-Blodgett films (vinylidene fluoride trifluoroethylene type) -- Epitaxial ferroelectric films with perovskite structure -- Homogeneous nondomain switching in the ferroelectric films at the nanoscale -- Possible application of the ferroelectric films at the nanoscale.