A mobile robot of the present disclosure emits a first patterned light downward and forward from a main body on a floor of an area to be cleaned and a second patterned light upward and forward from the main body, determines an obstacle based on an image of each emitted patterned light which is incident on the obstacle, and senses a tilt of the main body to compensate for the tilt. In this manner, an obstacle may be determined accurately, and after the tilt compensation, redetermination is made as to whether it is possible to pass through, so as to enable the mobile robot to pass through or bypass the obstacle. Accordingly, the mobile robot may reach a wider area to be cleaned, thereby extending the area that may be cleaned, and enabling fast determination and operation for effective traveling, such that the mobile robot may escape from an obstacle without being limited thereby.