1. A three-dimensional feature data generating device that generates three-dimensional data of a feature, from stereo images, and the three-dimensional feature data generating device includes: a stereo disparity calculating unit that calculates predicted value of stereo disparity relating to height information of the terrain and all the features; a line extracting unit that extracts the lines from an image, which are characteristic lines representing the internal structure of the rooftop of each feature, contour lines representing the external shape of each feature, and characteristic lines of each non-feature object; a line classification unit that classifies the lines extracted by the line extracting unit into three classes according to their respective meaning in the real world, i.e., the internal rooftop lines of features, external contour lines of features, and contour lines of shadow areas; a meaningless line eliminating unit that eliminates the lines that do not exist in the real world but are generated due to the influence of shadow or image noise; a line pair determining unit that determines, for each line in one image of the stereo image pair, its corresponding line in another image of the stereo image pair, based on the disparity information from the stereo disparity calculating unit, the color and texture distribution patterns of the neighboring region around each line, and also the line classification result; a stereo disparity correcting unit that calculates more precise disparity value based on the correspondence relationship of each line pair obtained by the line pair determining unit, to correct the predicted stereo disparity value obtained by the stereo disparity calculating unit; a line pair clustering unit that firstly selects, among all the line pairs obtained by the line pair determining unit, only the line pairs related to features including a residential building, an architectural structure and the like, and then utilizes both the disparity information of each line pair and the geometrical relationship of several line pairs to finally cluster the line pairs belonging to the same feature as one line pair cluster, a plane extracting unit that extracts basic planes configuring a feature based on the geometrical relationship and disparity information of the line pairs in each line pair cluster obtained by the line pair clustering unit; and a plane combining unit that calculates the three-dimensional relative location relationship between the planes of each feature extracted by the plane extracting unit to generate a three-dimensional model representing the whole structure of each feature.