A semiconductor memory device includes a first well region of a first conductivity type, first and second SRAM cells adjacently arranged to each other, the first and second SRAM cells each including at least a first transfer transistor and a drive transistor formed on the first well, the first transfer transistor and the drive transistor being coupled in series between a bit line and a power source line, and a first diffusion region of the first conductivity type arranged between the drive transistor of the first SRAM cell and the drive transistor of the second SRAM cell, to apply a first well potential to the first well.