This paper reports a new approach for the structural and morphological characterization of powders. It has been applied to characterize a nanostructured SnO2 material prepared by the gas phase condensation method. Transmission electron microscopy, X-ray diffraction, X-ray absorption spectroscopy and infrared spectroscopy have been used for the characterization of the samples. Besides the conventional fitting procedure of the EXAFS spectra, the mathematical method of factor analysis applied to the XANES spectra has been used to determine the percentage of amorphous phase existing in the samples after annealing at increasing temperatures up to 773 K. The results are confirmed by a FEFF simulation of the EXAFS spectra. The original powder was partially amorphous and was formed by very fine particles (d similar to 8-10 nm) linked in a fractal-like structure. No significant sintering occurs at T = 573 K, although the powder becomes more crystalline. At 773 K, sintering (d similar to 20-30 nm) and further crystallization takes place. Factor analysis has been also applied for the study of the FT-IR spectra of SnO2 nanoparticles and the results confirm semiquantitatively the degree of crystallization calculated from the analysis of the XANES spectra. The effective medium theory permits a description of the particle shapes that constitutes the crystalline component of the FT-LR spectra determined by factor analysis.