Semiconductor memory device with bit line and select line arrangement maintaining parasitic capacitance in equilibrium

A semiconductor memory device in which sensing of the memory information stored in a memory cell can be carried out stably, and reliably by equilibrating a parasitic capacitance existing between a select line and its adjacent bit line pair. Each Y select line YS is arranged at a position where it uniformly spans over both members of a bit line pair which extend straight in parallel to each other without the twist part TW within an area of four bit line pairs (eight bit lines or auxiliary bit lines) that are simultaneously sensed. Within an area of the first set of bit line pairs (BL0,BL0-)-(BL3,BL3-), in addition to the bit line pair (BL1,BL1-), the line pairs (BL0,BL0-) and (BL2,BL2-) with the twist part TW are substantially capacitance-coupled with the Y select line YS0. In these bit line pairs, the parasitic capacitance for the Y select line YS0 is at equilibrium between a bit line and an auxiliary bit line.