Disclosed herein is a semiconductor memory device including, a memory array with memory cells array-like arranged, a read bit line connected to a data output node of the memory cells and shared by a plurality of the memory cells arranged in one direction in the memory array, a write bit line connected to a data input node of the memory cells and shared by a plurality of the memory cells, a sense amplifier for sensing a voltage of the reading bit line, a first sense line and a second sense line connected to the sense amplifier, a read bit line switch for controlling electrical connection and disconnection between the first sense line and the read bit line, a write buffer connected between the second sense line and the write bit line, capable of controlling electrical connection and disconnection between the second sense line and the write bit line.