In the case where information is read from a selected memory cell, the transfer gate included in the memory cell is turned on, and one electrode of the memory cell capacitor is connected to one bit line of a corresponding bit line pair. At the same time, the other electrode of the memory cell capacitor, i.e. the cell plate electrode is connected to the other bit line of the corresponding bit line pair. As a result, a change of the potentials occur at both the bit lines of the corresponding bit line pair. This change of the potentials acts in the different directions between one bit line and the other bit line. Therefore, the read potential difference appearing on the bit line pair becomes larger, and malfunction of the sense amplifier is reduced, while the incidence of soft error can be reduced.