A semiconductor memory device that can achieve high-speed operation or that is highly integrated and simultaneously can achieve high-speed operation is provided. Transistors are disposed on both sides of diffusion layer regions to which capacitor for storing information is connected and other diffusion layer region of each transistor is connected to the same bit line. When access to a memory cell is made, two transistors are activated and the information is read. When writing operation to the memory cell is carried out, two transistors are used and electric charges are written to the capacitor.