SAR interferometry is the ideal tool for monitoring deformation fields, provided that they show some kind of spatial continuity and that the surface involved show a sufficient degree of geometric and electromagnetic stability. The technique has been successfully used to measure landslides, with radar image acquisitions separated by up to one and a half years. We how some results obtained by the French Space Agency in these domains. Our procedure makes use of the digital terrain model (DEM) of the area combined with two radar acquisitions. We believe this technique is the most appropriate for small moves detection since there always exists some kind of DEM in a given area. At worse, one could build the DEM using other data. Radar interferometry itself may provide the DEM if a 'motion free' time interval is available. Our studies indicate that the 'phase unwrapping,' often considered as a requirement of the interferometric technique, can be bypassed most of the time. This contributes to making this technique very user-friendly and allows us to hope it will spread widely very soon.