1. A map change detection device that detects changes in features that are targets described on a map, the map change detection device comprising: a stereo matching processor that, inputted with a plurality of images taken of predetermined regions from a plurality of different positions, extracts digital surface model data representing surfaces of the predetermined regions in three-dimensional coordinates; a feature height extractor that extracts feature heights where an elevation from ground level is subtracted from the digital surface model data extracted by the stereo matching processor; and a change detector that detects changes in a feature that is the target by comparing feature height data extracted by the feature height extractor and map data.