PURPOSE: To provide the marker of a mobile robot, information detector, and traveling controller in which it is possible to facilitate a countermeasure to the position and control information of the robot moving along an AGV guide line even when the information amounts are increased, it is possible to obtain the information while the robot is traveling, and it is possible to easily cooperate with the other mobile robot.

CONSTITUTION: A marker 1 is formed by adhering a reflecting tape 2 and a magnetic tape 3 divided into plural fields in which the information related with the mobile robot is written into two layers. Then, an information detector is formed of a reader 4 constituted of an optical sensor 4L and a magnetic sensor 4M which read the information of the pertinent marker, and an input and output port 11 which binarizes the output and transfers it to a CPU 12. Then, the traveling controller of the mobile robot is formed of the CPU 12 in which a memory 12m which temporarily stores the output of the pertinent input and output port, memory 12s which preliminarily stores the information related with each marker, and control program are installed, and a motor controller 13 which issues a driving instruction to a motor.