A lawn mower robot may include a plurality of distance sensor units. Each distance sensor unit detects distance information between the lawn mower robot and a fence for partitioning a region. A controller calculates adjacent direction information using each detected distance information. In addition, the lawn mower robot includes a position sensor module. The position sensor module detects position information related to the lawn mower robot. The controller detects whether the lawn mower has deviated from a preset region by using the position information. When the lawn mower robot has deviated, the lawn mower robot can be moved in a direction according to the calculated adjacent direction information and return along the shortest path.