PURPOSE: To judge the validity time limit of a prepaid card or the like even without a timer, by comparing the issuing data of records of said prepaid card or the like with the registering data of a memory, and updating said memory to a new issuing data if said registering date antedates.

CONSTITUTION: When an IC card is inserted in a card reader 1, the read data (B) of the issuing year, month, date is added with the valid term data (C) by an adder 5, so that the validity term limit data (D) of year, month and date is obtained. On the other hand, if the latest issuing data (A) of year, month and date in a memory 2 for storing the issuing year, month and date is antecedent to the issuing data (B) of the IC card, the read-out issuing data (B) is recorded as a newest data (A) through a discriminator 3 and an updating device 4. Then, in a discriminator 6, the latest issuing data (A) is compared with the validity term limit data (D). If the result is A≤D, the IC card is determined to be utilizable. In contrast, if the result is A>D, the fact that the IC card is invalid being displayed by a display device 7, and a processor 8 is brought in an inoperable state, thus stopping the service. Accordingly, the validity term can be judged with practically sufficient accuracy in the judging device even without a timer.