An exposure management system includes dosimeters, wireless relay devices that wirelessly communicate with the dosimeters, and a monitoring device. The dosimeters are carried by workers for measuring exposure doses in a radiation management facility. The wireless relay devices transmit a monitor indication message that requests the dosimeters to provide respective responses that include information of measured exposure doses. The wireless relay devices receive the responses from the dosimeters by using allocated respective communication channels that are different from each other. Each dosimeter receives the monitoring indication message and generates a designated number of response times for providing a response to the monitor indication message, and determines a communication channel corresponding to each of the generated response times. The monitoring device is connected to the wireless relay devices for monitoring an exposure state of each of the workers through the wireless relay devices and dosimeters.