RELAY COMMUNICATION DEVICE OF COMMUNICATION SYSTEM, DISPLAY MEDIUM OF COMMUNICATION SYSTEM, AND COMMUNICATION SYSTEM

PROBLEM TO BE SOLVED: To provide a relay communication device of a communication system, a display medium of the communication system and the communication system capable of being used at low cost, and performing communication regardless of material of mounting space.SOLUTION: In a communication system 1, when a user holds an information terminal 20 over a relay communication device 30, a terminal loop antenna 21 of the information terminal 20, and a relay loop antenna 31 of the relay communication device 30 transfer signals to each other by an electromagnetic induction system or an electromagnetic coupling system. By making a pair of conductive plates 42A, 42B of a display medium 40 and a pair of relay conductive members 32A, 32B of the relay communication device 30 face each other, signals are transferred by an electrostatic coupling system, and thereby a terminal control part 24 of the information terminal 20 communicates with an IC chip 41 of the display medium 40.