Is Radiation of Black Holes Observable?

If primordial black holes (PBH) saturate the present upper limit on the dark matter density in our Solar system and if their radiation spectrum is discrete, the sensitivity of modern detectors is close to that necessary for detecting this radiation. On the other hand, if PBHs constitute an essential part of dark matter in our Galaxy, their radiation, either discrete or continuous, is well within the modern sensitivity, and can be possibly distinguished from the radiation of other sources. Even with present data, we arrive at the upper limit on the fraction of PBHs in the dark matter of our Galaxy on the level of $10^{-4}$. None of our conclusions are in conflict with the upper limits on the explosions accompanying final stages of the evolution of PBHs