This paper presents a detailed description of an upgraded silicon surface barrier (SE) detector and analysis of X and gamma radiation and of the spectra given by it. The most frequently used application of these detectors was in measurements and analyses of alpha spectra. However, analysis of spectra gained here presented a silicon surface barrier detector showing possibilities of their wider application in various nuclear techniques and technologies. This specially referes to the feasibility of their use in the conditions that are different from those in laboratories, such as mines, surroundings of nuclear power plants etc. Recorded spectra from Co-57, show that SE detectors are very acceptable in nuclear laboratories for nuclear spectroscopy at room temperatures. On the contrary, field application in nuclear techniques connected with the protection of the environment and counting systems is much wider, and the detector temperature could reach 60 degrees C.