A method for controlling a robot cleaner comprising: recognizing a monitoring standby position, by a robot cleaner; moving to the monitoring standby position at a monitoring start time, by the robot cleaner; acquiring an image at the monitoring standby position, by an image acquisition unit of the robot cleaner; determining whether an event occurs, by the robot cleaner, based at least on the image acquired by the image acquisition unit; and transmitting the image acquired by the image acquisition unit to an external remote terminal when it is determined that the event occurs; characterised in that the moving to the monitoring standby position comprises: determining whether there is an obstacle at the monitoring standby position in a procedure of moving to the monitoring standby position; moving to a changed monitoring standby position at which the obstacle is avoided, by the robot cleaner, when there is the obstacle at the monitoring standby position; determining whether a distance between the monitoring standby position and the changed monitoring standby position is greater than a predetermined distance; and transmitting a message for changing the monitoring standby position when the distance between the monitoring standby position and the changed monitoring standby position is greater than the predetermined distance. recognizing a monitoring standby position, by a robot cleaner; moving to the monitoring standby position at a monitoring start time, by the robot cleaner; acquiring an image at the monitoring standby position, by an image acquisition unit of the robot cleaner; determining whether an event occurs, by the robot cleaner, based at least on the image acquired by the image acquisition unit; and transmitting the image acquired by the image acquisition unit to an external remote terminal when it is determined that the event occurs; characterised in that the moving to the monitoring standby position comprises: determining whether there is an obstacle at the monitoring standby position in a procedure of moving to the monitoring standby position; moving to a changed monitoring standby position at which the obstacle is avoided, by the robot cleaner, when there is the obstacle at the monitoring standby position; determining whether a distance between the monitoring standby position and the changed monitoring standby position is greater than a predetermined distance; and transmitting a message for changing the monitoring standby position when the distance between the monitoring standby position and the changed monitoring standby position is greater than the predetermined distance. determining whether there is an obstacle at the monitoring standby position in a procedure of moving to the monitoring standby position; moving to a changed monitoring standby position at which the obstacle is avoided, by the robot cleaner, when there is the obstacle at the monitoring standby position; determining whether a distance between the monitoring standby position and the changed monitoring standby position is greater than a predetermined distance; and transmitting a message for changing the monitoring standby position when the distance between the monitoring standby position and the changed monitoring standby position is greater than the predetermined distance.