The model of V. L. Gurevich et al. which describes superconductivity of degenerate semiconductors due to the interaction of carriers with longitudinal optical phonons is used to calculate the critical superconducting temperature T//c. The dependence of T//c on the electron density parameter and on the crystal ionicity is determined. It is found that the maximum T//c which can be achieved within the Gurevich-Larkin-Firsov model is of the order of 0. 3 degree K.