We present the results of analytical and numerical study of spatial distribution of the fluctuating electric field near the surface of a model ionic crystal as a function of temperature. The potential variance is calculated and it is shown that the fluctuating field power density decays outside of the crystal as h-3, where h is the distance from the crystal suface. When h > 6a (a is the lattice period), the fluctuating field exceeds the static field, which decays exponentially. At these distances, the chatacteristic strength of the fluctuating field lies in the range of 106V/cm. The fluctuating potential variance squared grows linearly at high temperatures and does not vanish at 0 K. The effect of the fluctating electric field on formation of nanostructures on the crystal surface is considered.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.