In this paper a dynamic method of analysis of the reflectance is presented starting form a polychromatic interferometric system that allows establishing the conte of materials to microscopic scale. The reflectance of the material is obtained starting from the distribution of intensities in the optical contact of an interferometric microscopic, where a device that can carry out displacement of the order of the nanometers in axial address was adapted, the interference pattern detection was carried out with a CCD in color. The determination of the local reflectivity realizes the presence of the materials that form the sample to microscopic, scale; given the nano technologies peak this method will allow to characterize with more resolution the composition of new materials.