This program processes digitized spectrometric data from ionizing radiation in online mode. It focuses mainly on analysis of neutron and gamma radiation. Various libraries are added to this program that enable it to communicate with different digitizers. These libraries provide the program with interface of digitizer. Online spectrum processor sets up digitizer, reads impulse data from digitizer and separates these impulses with one of available separation methods. This is necessary to distinguish impulses created by different particles in mixed fields. After separation it is possible to generate apparatus spectrum. Additionally the program contains editable database of calibration points and response functions. With calibration data it can calculate energetic spectrum and using response function it can calculate final neutron or gamma spectrum with Expectation Maximization algorithm. These spectra can be updated as the program continuously analyses new incoming impulses.