Analysis of spectral data of two neighboring infrared lines, Fe i 15648.5 Å (g = 3) and Fe i 15652.9 Å (g_eff = 1.53) are carried out for a simple sunspot when it was near the solar disk center (mu = 0.92), to understand the basic structure of sunspot magnetic field. Inversions of Stokes profiles are carried out to derive different atmospheric parameters both as a function of location within the sunspot and height in the atmosphere. As a result of the inversion we have obtained maps of magnetic field strength, temperature, line-of-sight velocity, field inclination and azimuth for different optical depth layers between log (tau_ {5}) = 0 and log (tau_ {5}) = -2.0 . In this paper we present few results from our inversion for a layer averaged between log (tau_ {5}) from 0.0 to -0.5.