Ultrathin ferroelectric Langmuir-Blodgett films were prepared from the ferroelectric copolymer of vinylidene flouride with trifluorethylene P(VDF-TrFE). The minimum thickness of the ferroelectric film was about 35 Angstrom, (seven monomolecular layers of the copolymer). The ultrathin films show ferroelectric switching measured by the pyroelectric effect.