A robot system is provided and includes an autonomous mobile robot. In the system in which monitoring is performed using the autonomous mobile robot which travels along a predetermined path, an interval between the time when a user requests transmission of images and the time when the user obtains the images may be reduced. The autonomous mobile robot travels along a predetermined path at predetermined times, a camera takes photographs at predetermined locations during the travel along the predetermined path, images taken by the camera are stored, and the stored images are sent to a requesting cell phone in response to a transmission request from the cell phone.