The influence of the changes in the structure of near-surface region of a lithium niobate Z-cut single crystal grown from a congruent melt on the characteristics of the low-energy cathodoluminescence has been investigated. It is shown that radiation spectra strongly depend on the structure of the near-surface region. The luminescent properties of the crystal annealed in air at 950 degrees C in contrast with those of the polished crystal are found to be stable against the bombardment of the crystal by electrons with energy at least up to 1.3 keV. The effect of electron bombardment of the crystal face on the radiation spectra taken from the opposite face was observed.