Today, single photon imaging represents one of the most challenging goals in the field of photonics. Many areas are involved: nuclear and particle physics, astronomy, and, in the biophysics field, the newest technique to investigate the state of several biological systems by detecting the ultra-weak luminescence emitted from the excited sample under study. Aim of the work is the realization of a single photon imaging device able to identify the position and the arrival time of the impinging photons from ultra low intensity sources. The main features of a 2-D array of Single Photon Avalanche Diodes, manufactured by ST-Microelectronics, are shown.