This work presents the results of studying the electrophysical properties of the YCu0.15Mn0.85O₃ solid solution in the range of temperatures of T = 26–400∘C and frequency range of f = 10²–10⁵ Hz. A model description of the revealed dispersion of dielectric parameters in the material is made. The nonclassical modified Havriliak–Negami model written for complex electrical conductivity was used as an approximation model. It is shown that the application of this model almost exactly describes the frequency behavior of the dielectric constant 𝜀′/𝜀0( f), the dielectric loss tangent tgδ( f) as well as the real and imaginary parts of complex conductivity γ′( f) and γ′′( f). The results of this work are an important step in identifying the opportunities and understanding the applications of this model.This work presents the results of studying the electrophysical properties of the YCu0.15Mn0.85O₃ solid solution in the range of temperatures of T = 26–400∘C and frequency range of f = 10²–10⁵ Hz. A model description of the revealed dispersion of dielectric parameters in the material is made. The nonclassical modified Havriliak–Negami model written for complex electrical conductivity was used as an approximation model. It is shown that the application of this model almost exactly describes the frequency behavior of the dielectric constant 𝜀′/𝜀0( f), the dielectric loss tangent tgδ( f) as well as the real and imaginary parts of complex conductivity γ′( f) and γ′′( f). The results of this work are an important step in identifying the opportunities and understanding the applications of this model.