To provide an apparatus and a method for writing data for IC chips capable of increasing the speed of processes while solving security problems with a method of subtracting from a retry counter prior to processing even if a caching system is employed for a multi-application IC card having a virtual machine incorporated therein, and guaranteeing the security of the IC card.

The apparatus for writing data for IC chips includes a virtual machine, a processing unit for processing designated data in response to instructions from the virtual machine, a cache memory for temporarily accumulating the data processed by the processing unit, and a nonvolatile memory for writing data output from the cache memory, in response to writing instructions from the processing unit. When processing computations about secret information, the processing unit writes the data accumulated in the cache memory to the nonvolatile memory prior to execution of the computations.