Abstract: A semiconductor device includes a body including conductive layers stacked and spaced from each other in a first direction and first and second areas along a second direction intersecting the first direction, an insulating portion extending along the directions in the areas and dividing the conductive layers in a third direction intersecting the directions, first columnar portions extending along the first direction in the first area and including a semiconductor layer, memory cells being formed at intersections between the conductive and semiconductor layers, second columnar portions extending along the first direction in the second area and including an insulator, third columnar portions extending along the first direction in the second area and including a semiconductor layer, and contacts extending along the first direction in the second area and connected to a conductive layer. The second portions are arranged along the insulating portion on both sides thereof in the third direction.