Memory card

Disclosed is a memory card which ensures high-speed data writing operations. The memory card is formed of an erasable and programmable nonvolatile memory and a control circuit. A memory array of the nonvolatile memory has an erasing table including a first flag designating whether a memory area is a vacant area or not in every erasing unit. The control circuit exercises, when the number of memory areas in which the erasable data is written becomes a constant value, pre-erasing control to previously erase the erasable data over the memory area depending on the first flag indicating a vacant area. Since the erasing process is previously executed to the vacant memory area, necessity for insertion of the erasing process just before the writing process using the vacant memory area can be reduced and thereby writing data to the memory card can be highly speeded.