A mobile robot with a single camera, comprising: a detection unit having a single camera, and configured to sequentially capture images including a ceiling with using the single camera in a moving state of the mobile robot on a cleaning region; characterized in that: the mobile robot further comprises a control unit configured to extract feature points from the sequentially-captured images, to match at least one same feature point of two neighboring images, and to extract 3D information of a substantial feature point of surroundings, and thereby to make a 3D map; wherein the control unit is further configured to generate a preset number of particles on a virtual line based on matching information of the same feature points of two neighboring images, to project the generated particles to a second image of the two neighboring images, to select one particle among the projected particle as the substantial feature point, and to extract 3D information of the substantial feature point based on a correlation between the projected particles and the at least one same feature point of the second image, wherein the virtual line passes through both a center of the camera and the substantial feature point of a first image of the two neighboring images, wherein the plurality of particles are initially set to have the same interval and the same weight on the virtual line. a detection unit having a single camera, and configured to sequentially capture images including a ceiling with using the single camera in a moving state of the mobile robot on a cleaning region; characterized in that: the mobile robot further comprises a control unit configured to extract feature points from the sequentially-captured images, to match at least one same feature point of two neighboring images, and to extract 3D information of a substantial feature point of surroundings, and thereby to make a 3D map; wherein the control unit is further configured to generate a preset number of particles on a virtual line based on matching information of the same feature points of two neighboring images, to project the generated particles to a second image of the two neighboring images, to select one particle among the projected particle as the substantial feature point, and to extract 3D information of the substantial feature point based on a correlation between the projected particles and the at least one same feature point of the second image, wherein the virtual line passes through both a center of the camera and the substantial feature point of a first image of the two neighboring images, wherein the plurality of particles are initially set to have the same interval and the same weight on the virtual line. the mobile robot further comprises a control unit configured to extract feature points from the sequentially-captured images, to match at least one same feature point of two neighboring images, and to extract 3D information of a substantial feature point of surroundings, and thereby to make a 3D map; wherein the control unit is further configured to generate a preset number of particles on a virtual line based on matching information of the same feature points of two neighboring images, to project the generated particles to a second image of the two neighboring images, to select one particle among the projected particle as the substantial feature point, and to extract 3D information of the substantial feature point based on a correlation between the projected particles and the at least one same feature point of the second image, wherein the virtual line passes through both a center of the camera and the substantial feature point of a first image of the two neighboring images, wherein the plurality of particles are initially set to have the same interval and the same weight on the virtual line.