Thermodynamics of the 1D ferroelectric model with proton tunneling has
been reduced to the calculation of the grand partition function of th
e 1D Ising model of spin S = 1 in the transverse field Gamma. This all
ows the behavior of the initial model to be calculated in the vicinity
of its thermodynamic anomaly. In the second order, the dependence of
the free energy on temperature and the tunneling parameter Gamma was f
ound.