Nuclear level density (NLD) is calculated using the statistical partition function method for 58Ni. The microscopic recursive approach based on the realistic single particle levels schemes obtained from various nuclear potentials is used to remove various simplifying approximations and accurately determine the NLD. The effect of these approximations is determined by comparing the results of this method with the usual and common calculations of the Fermi gas model (FGM). It is shown that such a fully microscopic approach represents the NLD behavior according to the available experimental data.