Abstract: There are provided an IC card and a communication system, wherein the IC card is enabled to be connected with a different infrastructure. The communication system using the IC card comprises a PC (20) provided with an IC card-inlet slot, an IC card unit (10), and an external communication apparatus (30) connected with the IC card unit (10); wherein the card is provided therein with a radio portion (12) and a radio controlling portion (13) for performing data communication, an interface (18) to be connected with the external communication apparatus (30) for enabling data communication with infrastructure (2), a memory (17) for storing data of each infrastructure to be periodically renewed, and a card controlling portion (16) for selecting an infrastructure on the basis of data of the infrastructure stored in the memory (17) for executing data communication between the infrastructure thus selected and the PC (20).