[en] The Silicon Photomultiplier (SiPM) is a semiconductor device consisting of many photon microcounters (10³ mm^-2) positioned on a common Si substrate. SiPM operates in a limited Geiger mode and has single photoelectron gain (10⁶) and photon detection efficiency (20%) similar to vacuum PMT. Main SiPM features are described and a number of examples of its possible applications are demonstrated, such as scintillator fiber readout, scintillator tiles+WLS readout, imaging Cherenkov counter timing. These SiPM applications are based on experimental test data and SiPM performance is compared with other photodetectors (PMT, APD, HPD, VLPC)