The synthetic aperture radar image processing device includes time-series analysis unit which extracts persistent scatterers from time-series observation data for the observation direction for an observation area observed from multiple observation directions by a radar, and calculating displacement speeds of the extracted persistent scatterers, clustering unit which generates reflection point clusters by clustering extracted persistent scatterers based on their phase and position, distance calculation unit which calculates a distance between each of the persistent scatterers included in the reflection point clusters and each structure included in the observation area, representative value calculation unit which calculates each representative value for the distance between each persistent scatterer and each structure, for each reflection point cluster, and corresponding structure determination unit which associates the structure corresponding to the smallest representative value with the persistent scatterer, for each reflection point cluster.