A robot cleaner comprising: a main body; a pattern projection unit projecting light in a predetermined pattern to the cleaning area; an image acquisition unit acquiring an image by photographing an area to which the patterned light is projected; and a controller performing feature detection on predetermined pixels in the acquired image obtained by the image acquisition unit so as to detect a segment formed by consecutive feature pixels according to a feature detection result characterized in that the controller includes: a pattern detection module detecting a light pattern which is generated according to patterned light projected from the pattern projection unit indicated in the acquired image; and a validity determination module checking validity of detected patterns, wherein, the validity determination module discriminate a valid pattern formed by light directly projected from the robot cleaner from a pattern formed by light reflected from a floor or an object, from among patterns indicated in the acquired image, on the basis of geometrical characteristics defined by a projection direction of the light and the direction of an optical axis in which the image is acquired when two or more patterns are detected from the image due to reflection of the light from a floor or an object. a main body; a pattern projection unit projecting light in a predetermined pattern to the cleaning area; an image acquisition unit acquiring an image by photographing an area to which the patterned light is projected; and a controller performing feature detection on predetermined pixels in the acquired image obtained by the image acquisition unit so as to detect a segment formed by consecutive feature pixels according to a feature detection result characterized in that the controller includes: a pattern detection module detecting a light pattern which is generated according to patterned light projected from the pattern projection unit indicated in the acquired image; and a validity determination module checking validity of detected patterns, wherein, the validity determination module discriminate a valid pattern formed by light directly projected from the robot cleaner from a pattern formed by light reflected from a floor or an object, from among patterns indicated in the acquired image, on the basis of geometrical characteristics defined by a projection direction of the light and the direction of an optical axis in which the image is acquired when two or more patterns are detected from the image due to reflection of the light from a floor or an object. a pattern detection module detecting a light pattern which is generated according to patterned light projected from the pattern projection unit indicated in the acquired image; and a validity determination module checking validity of detected patterns, wherein, the validity determination module discriminate a valid pattern formed by light directly projected from the robot cleaner from a pattern formed by light reflected from a floor or an object, from among patterns indicated in the acquired image, on the basis of geometrical characteristics defined by a projection direction of the light and the direction of an optical axis in which the image is acquired when two or more patterns are detected from the image due to reflection of the light from a floor or an object.