A memory card has external interface terminals, an interface controller connected to each of the terminals, a rewritable nonvolatile memory connected to the interface controller, and a data processor connected to the interface controller. The interface controller can perform an operation based on another command supplied from the outside in parallel with the operations of transferring a command for a data process supplied from the outside to the data processor and operating it. The interface controller has plural buffers and, after completely inputting the command for a data process from an outside to a first buffer of the plural buffers, allows data related to the other command supplied from the outside to be inputted to a second buffer of the plural buffers. The memory card can receive a command data and data to be processed subsequently from the outside without the need of waiting for the completion of the communication process between the data processor and the interface controller.