The performance of a home made X-ray Powder Diffractometer is presented. The diffractometer has the Debye Scherrer geometry and is equipped with an elliptic Gobel mirror. Although the amount of samples is small (capillary mounting), the high flux of the focusing mirror ensures spectra of good quality, in measuring times and intensities comparable to the ones taken with a Bragg-Brentano diffractometer. A series of measurements from standard samples mounted in capillaries with different diameters is presented. The analysis of the spectra with the Rietveld method has shown that the most crucial correction for an effective refinement is the absorption one.