A contactless IC card (smart card) includes a communication module for making communication with an external device by contactless communication, a nonvolatile memory in which data can be written or rewritten and a control element. The contactless IC card performs a process in response to a command given from the external device. The process that can be performed by the contactless IC card is defined by ISO/IEC14443, for example. In ISO/IEC14443, an initialization and anti-collision process of making communication with one contactless IC card selected from a plurality of contactless IC cards with which the external device can communicate and a command process by use of a block transfer protocol (T=CL) successively performed after the above process are defined.