Nitrogen K-edge electron energy loss near-edge structure (ELNES) spectra of thin SiNx films were measured with a small scattering angle in the reflection mode for the first time. The SiNx films were formed by low pressure chemical vapour deposition (LPCVD) on silicon oxide layers with or without rapid thermal nitridation (RTN) pretreatment. The ELNES spectra were found to be similar to the X-ray absorption near-edge structure (XANES) spectra, and to be sensitive to the outermost SiNx structures. The ELNES spectra of the silicon oxide and SiNx films with RTN pretreatment were similar and independent of the thickness. The ELNES spectra of the SiNx films with RTN pretreatment and a thicker SiNx film (7.7 nm) without RTN pretreatment were also similar. However, very thin SiNx films (thickness, 0.4 or 0.6 nm) without RTN pretreatment showed slightly different ELNES spectra from the thicker film without RTN pretreatment and SiNx films with RTN pretreatment.