According to one embodiment, a semiconductor storage device includes a stacked body, a columnar body, a conductive member, a plate-like portion, and a dividing portion. In the stacked body, a plurality of conductive layers and a plurality of insulating layers are alternately stacked one by one, and a stepped portion including the conductive layers is formed to be faced to an end in a first direction. The columnar body penetrates the stacked body, and includes a memory cell formed in a portion facing the conductive layer. The conductive member is electrically connected to the columnar body below the stacked body, and extends to a region laterally below the stacked body beyond the stepped portion in the first direction. The plate-like portion extends in a stacking direction of the stacked body in a lateral region of the stacked body to reach the conductive member, and extends in a second direction intersecting the first direction. The dividing portion is disposed in the conductive member on the stepped portion side with respect to the plate-like portion, partially divides the conductive member, and includes an insulating material.