Prospects of using silicon photomultipliers for the astroparticle physics experiments EUSO and MAGIC

We discuss the silicon photomultiplier (SiPM) as a novel photon detector for the astroparticle experiments MAGIC and EUSO. For these experiments we pursue two different developments of the SiPM. One development is pursued at MEPhI, where prototypes are available, and we will describe some characteristics. The second development, which is using the back illumination principle is at present in its design phase.