Effects of the surface atomic structures on the electron spectrum and luminescent properties of porous silicon (por-Si) were studied by methods of photoluminescence spectroscopy, UV photoelectron spectroscopy, and Fourier-transform IR spectroscopy. An analysis of evolution of the por-Si characteristics in the course of thermal treatment in vacuum revealed a correlation between the photoluminescence spectrum and intensity, on the one hand, and the electron spectrum and surface atomic structure, on the other hand. The thermodesorption of adsorbate from por-Si leads to atomic rearrangements on the sample surface, which is accompanied by changes in the electron structure and, hence, in the luminescent properties of the material.