The analysis of plasma thermodynamics is necessary in the following areas: plasma technologies, high energy density processes in fusion devices, astrophysical simulations, and calculations of the atmospheric entry. The pressure, specific internal energy, specific entropy, thermal conductivity, electrical conductivity, and absorption coefficients in a wide range of temperatures and densities are obtained by joining the results of the finite temperature Thomas–Fermi model with the ionization equilibrium model (Saha–Boltzmann equations). Data is presented for copper. The results are analyzed in the area of the common applicability of these models to find the criterion for each use of the model.