You can use Extract by Mask tool, it's here clip DEM with a polygon shapefile clip DEM by polygon in ArcGIS - YouTube
Thanks a lot ! I used the clip function to have a DEM with the shape of my basin but it didn t work.. But with extract by mask tool it works !
Hi,
From a 'most recent data format' perspective you should use your DEM Raster as a mosaic dataset (of type elevation, which will be useful in other ways like stretching, ... see documentation). Your boundary shaepfile can then be loaded into the mosaic as just that - the boundary - and you are all set for analysis