SEMICONDUCTOR MEMORY DEVICE

According to one embodiment, a semiconductor memory device includes a first staircase portion that is arranged in a staircase region at a position that overlaps a plate-like portion in a stacking direction, in which a plurality of conductive layers is terraced in a first direction; and a second staircase portion and a third staircase portion arranged in the staircase region on both sides in a second direction of the plate-like portion, and having structures in each of which the plurality of conductive layers is terraced, and that are mutually inverted in the second direction with respect to the plate-like portion. A plurality of first plugs is individually arranged at different positions in the second direction relative to the plate-like portion, depending on positions in the first direction, and a plurality of second plugs is individually arranged at positions inverted in the second direction from the respective positions of the plurality of first plugs, with respect to the plate-like portion.