1. A localization apparatus comprising: an image sensor which captures an image and outputs image data; a range sensor which outputs a range sensing signal; an image feature point information processing unit configured to extract image feature points from the image data output by the image sensor and generates image feature point information about the extracted image feature points; a range feature point information processing unit which generates range feature point information about range feature points from the range sensing signal; and a state estimation unit which estimates a state variable comprising a position of the localization apparatus by using the image feature point information and the range feature point information as an observation value.