1. An autonomous mobile body which moves in a movement region while recognizing a self-position of the autonomous mobile body, the autonomous mobile body comprising: a sensor that measures, by emitting a beam, a distance from the sensor to each of a plurality of obstacles located in the movement region; and self-position recognizing circuitry that recognizes the self-position by (i) calculating a self-position candidate in accordance with the distance and designating the distance as a sensor distance, (ii) comparing the sensor distance with a map distance which extends from the self-position candidate to the each of the plurality of obstacles and which is calculated in accordance with an environment map containing information on a position of the each of the plurality of obstacles and (iii) correcting the self-position candidate, wherein the self-position recognizing circuitry includes clustering circuitry that (i) groups distance measurement points of the each of the plurality of obstacles into clusters, the distance measurement points having been measured by use of a beam emitted from the sensor and (ii) recognizes the each of the plurality of obstacles, and the clustering circuitry calculates a feature amount of a shape of each of the clusters in accordance with a distribution of obstacle measurement points belonging to each of the clusters.