PURPOSE: To provide a cyclic robot system in which guard efficiency is improved and continuous cyclic monitoring service can be performed.

CONSTITUTION: At a normal time, a moving mechanism means 1 on which a sensor means 2 is mounted is moved along the route 7 installed in a cyclic area. When an abnormal state is detected by a sensor means, the operator disposed in a disaster prevention center watches at the image 10 obtained by an ITV camera 3 and performs the confirmation of the abnormality. The operator takes the necessary measure according to the contents of the abnormality, converses with a doubtful man by interphone devices 5 and 9 and controls an external device 19 by a wireless remote controller 11. The positional control of the moving mechanism means is performed based on the number of the rotation of a wheel and the distance instruction means on the route.