The semiconductor memory device includes: a first well of a first conductivity type, a second well of the first conductivity type and a third well of a second conductivity type formed in a substrate: a diffusion bit line extending in a row direction and a word line extending in a column direction both formed in the second well; a plurality of semiconductor memory elements arranged in a matrix, each connected with the diffusion bit line and the word line; a selection transistor formed in the first well for applying a voltage to the diffusion bit line; and a forward diode formed of a diffusion layer of the first conductivity type formed in the third well and the third well. The diffusion bit line, the forward diode and the source of the selection transistor are electrically connected with one another.