To easily enable positive ascertainment of a vehicle which is a subject of maintenance even at the time when a plurality of vehicles are lined up in a confined area.

A contact type IC card 1 is used and attached to a data processing device 2 provided for a vehicle maintenance station, and the IC card has a customer information area 11A, an vehicle-specific information area 11B, and a vehicle history information area 11C. Then vehicle control information read from the memory 11 of the attached IC card 1 is displayed on-screen at a data displaying part 25 of the data processing device 2, thus ascertainment of the vehicle which is the subject of maintenance can be easily performed. At the time when input is done from a sales input part 26 when the maintenance is finished, the information on the settlement of accounts and the information on the maintenance are displayed on-screen at the data displaying part 25, and are printed out from a receipt printer 28, thus its contents can be ascertained.