PURPOSE: To copy data in the same storage device in extremely short time by connecting a control means including a transfer gate between the 1st and 2nd storage circuit groups consisting of static storage circuits and controlling the switching of the transfer gate in accordance with a control signal.

CONSTITUTION: A data transfer control circuit 36A consisting of an inverter 33 and a data transfer MOSFET35 is connected between an other data storage node 20 in one memory cell 10A and another data storage node 18 of the other memory cell 10B. Similarly, a data transfer control circuit 36B consisting of an inverter 33 and a data transfer MOSFET35 is connected between a self-data storage node 18 of one memory cell 10A and a self-data storage node 20 of the other memory cell 10B. A unit storage element m for one unit has two static type memory cells 10A, 10B and both memory cells 10A, 10B are coupled with each other through two data transfer control circuits 36A, 36B.