A robot cleaner includes a controller configured to sense an obstacle with a sensing unit of the robot cleaner, and control a driving unit of the robot cleaner to move a main body of the robot cleaner forward into a first contact state in which a front end of a cleaning unit cleans a first region while in contact with the obstacle. After the first contact state, the controller controls the driving unit to move the main body according to a predetermined connecting operation into a second contact state in which the front end of the cleaning unit cleans a second region while in contact with the obstacle, the first region and the second region being arranged along an outline of the obstacle.