1. A localization device of a mobile robot, comprising: a storage unit to store characteristic information of a reference object; a characteristic information extracting unit to extract and respectively identify, from data sensed by the mobile robot at an initial location of the mobile robot, characteristic information of the reference object and characteristic information of the surroundings of the reference object; a registration unit to match the characteristic information of the reference object and the characteristic information of the surroundings of the reference object sensed at the initial location of the mobile robot, with the stored characteristic information of the reference object, to derive, based on the matching, reference characteristic information including reference characteristic information of the reference object and reference characteristic information of the surroundings of the reference object, and to register the reference characteristic information as corresponding to the reference object, the characteristic information of the surroundings of the reference object comprising information of the background around the reference object; and a location estimation unit to estimate a location of the robot using the reference characteristic information.