To provide an IC card system capable of easily deleting the unnecessary application mounted on an IC card without bothering an IC card user, without cooperation between an operation system and a service system.

In response to a service releasing request, a card control part 22 of the service system 2 transmits a management information write command for setting a deleting flag to the IC card 1. A card control part 11 of the IC card 1 sets the deleting flag of the application of a management table 12 to " possible ". A card control part 32 of the operation system 3 transmits a management information readout command to the IC card 1. An area determining part 33 determines a shortage of a memory when downloading the new application on the basis of management information, and a flag determining part 34 specifies the application to be deleted on the basis of the management information. The card control part 32 transmits a deleting command of the specified application to the IC card 1.