Semiconductor memory device having sense amplifiers shared between open bit lines less affected by adjacent ones

A semiconductor dynamic random access memory device has first open bit lines (BL0-BL3) arranged in parallel and second open bit lines (CBL0-CBL3) respectively paired with the first open bit lines so as to form bit line pairs and a sense amplifier (SA11) shared between the bit line pairs so as to increase the magnitude of a potential difference indicative of a data bit sequentially supplied from the bit line pairs, and either high or low level indicative of the data bit is supplied to both first and second bit lines of the selected bit line pair upon completion of the sense amplification, thereby equalizing electric influence on the adjacent open bit lines.