Due to its high dielectric constant silicon nitride (Si3N4) is considered to be a perspective material for dielectric nanolayer in nanocapacitors. It is proposed to use the Si3N4 in nanocapacitors forseen for applications in harsh conditions, such as space environment. In the conditions where exposure to ionizing radiation is possible, radiation stability of the material is of great importance. Formation of radiation-induced defects, breaking of chemical bonds and formation of voids can affect performance of a nanocapacitor. To estimate the influence of ionizing radiation on Si3N4 dielectric nanolayers, it is important to characterize composition of chemical bonds and their changes caused by the ionizing radiation. Radiation stability of single- and multilayered Si3N4 of different thicknesses was investigated. The samples were synthesized as a SiO2/P-doped polySi/Si3N4 stack on Si wafer. Si3N4 layers were deposited in a low pressure chemical vapour deposition (LPCVD) process using SiH4 and NH3 as reactant gases. The samples were irradiated with accelerated electrons (5 MeV) generated by a linear electron accelerator (ELU-4), absorbed doses up to 10 MGy. Chemical bonds in non-irradiated and irradiated samples were analyzed by means of Fourier transformation infrared (FT-IR) spectrometry (Bruker Vertex 70v). The results showed that chemical bonds in the synthesized single- and multilayered Si3N4 remained stable up to absorbed doses 10 MGy.