[en] Silicon Photo-Multipliers (SiPMs) at cryogenic temperatures are very promising for the realization of scintillation light detectors to be adopted in particle physics experiments dedicated to neutrino and Dark Matter searches. For these reasons, we tested several devices from different manufacturers with particular emphasis to breakdown voltage, dark current and gain changes at different temperatures. The system, based on a cryo-pump with a cold head, permits to scan the temperature from 300 K down to 50 K. A second system, based on a climatic chamber, was also used. We found that all devices can be operated at cryogenic temperatures. Furthermore, the thermal component of the noise decreases at low temperature, thus allowing the use of the device at higher overvoltage.