To reduce power consumption by reducing a current during holding data.

A signal generating means 8 latches only data required to hold data to a sense amplifier 5 and holds it, and self-refresh operation is performed by storing data held in the sense amplifier 5 in the original memory cell 2. And holding data is performed by only supply of a standby current (holding data) being almost same as a SRAM with a cost and chip size being almost same as DRAM/pseudo-SRAM by decreasing a memory region in which data is held to only a specific memory cell 2 and holding data in the sense amplifier 5, and power consumption of the device can be reduced largely.