A robot vacuum cleaner has a driving unit moving a cleaner body on a cleaning surface; a distance detecting unit detecting a distance of travel by the driving unit; an obstacle detecting unit detecting an obstacle near the cleaner body; and a central processing unit moving the cleaner body to a location a certain distance away from the obstacle according to a cleaning travel pattern when the obstacle detecting unit detects an obstacle, and variably applying the distance as the obstacle is detected and outputting a travel signal to the driving unit, thereby evenly covering the cleaning area.