IC card and OS activation method for the same

In an IC card applicable to a plurality of data transfer methods and including a plurality of OSs, when power sufficient for the operation is supplied to the IC card, an initial OS selecting section activates one of the plural OSs as an initial OS on the basis of identification information stored in a nonvolatile memory. A transfer method determining section determines a data transfer method on the basis of data received from a reader/writer. An OS applicability determining section determines whether or not the determined data transfer method accords with a data transfer method corresponding to the currently employed OS. When the data transfer methods do not accord with each other, an OS switching section switches the currently employed OS to another OS.