<title>Catania Astrophysical Observatory facility for UV CCD characterization</title>

We describe the instrumental apparatus developed at the Catania Astrophysical Observatory to characterize the CCDs detectors for the 'spectrum UV' space observatory. The system allows us to perform a full characterization of the electro-optical properties of CCDs. In particular the system is designed to measure the CCDs quantum efficiency (QE) in the wavelength range 1300 - 11000 angstrom. The main components of the instrumental apparatus are a deuterium and a xenon lamp as radiation sources, a monochromator as light disperser, a series of filters to minimize the contribution of the straylight and the second order of the gratings and a series of NIST calibrated photodiodes as reference detectors. For measurements below 2000 angstrom the system is operated under vacuum conditions. The short wavelength cutoff is due to the use of MGF<SUB>2</SUB> optics. The CCDs are operated using different CCD controllers, one developed for the Catania Astrophysical Observatory and the other one for the Italian National telescope 'Galileo.' Here we report on the performances of the instrumental apparatus and also present results on the QE of a CCD chip manufactured by EEV.