The present embodiment relates to a lawn mower robot. A lawn mower robot includes a body having a moving device; a mowing device disposed in the body and mowing lawns; a sensor disposed in the body and receiving light signal from the outside; and a controller controlling the moving device and mowing device, wherein, when the sensor senses the light signal, the controller allows the mowing device to be operated, and when the sensor does not sense the light signal, the controller allows the mowing device to be stopped.