ETC ON-VEHICLE MACHINE

PROBLEM TO BE SOLVED: To prevent illegal use that an on-vehicle machine is displaced on a vehicle other than a contracted vehicle in an ETC (automatic toll receiving) system. SOLUTION: Vehicle information, etc., from an IC card for an on-vehicle machine setup is stored not in a security part 8 as in a conventional manner but in a nonvolatile memory 13 fed from a power supply part 11 using a vehicle battery as power supply. Because the vehicle information, etc., stored in the memory 13 are eliminated if the vehicle power supply of an on-vehicle machine is disconnected to mount the on-vehicle machine on another vehicle for illegal use, communication with roadside radios can not be preformed so that the illegal use can be prevented. In such a case, the setup to be made by the illegal user again is prevented by locking the ID card in an unreadable state.