PURPOSE: To speed up a writing action by setting the action speed of a semiconductor dynamic memory IC used in the error correction code memory area of a memory array part faster than the action of a one used in a data bit group memory area.

CONSTITUTION: The memory array part (storage part) consisting of the semiconductor dynamic memory ICs is provided with the data bit group memory area 11-1 and the error correction code memory area 11-2. The IC to which the action speed is faster than that of the semiconductor dynamic memory IC constituting the memory 11-2 is used for the semiconductor dynamic memory IC constituting the area 11-1. Thus the speed of the action to write error correction code information 14 can be the same as that to write data bit information 13, thereby eliminating the loss of write cycle time. Thus the write action speed to a memory card can be increased and cost reduction is attained.