According to one embodiment, a semiconductor device comprising: a first stacked structure in which first insulating layers and first conductive layers are alternately stacked; a second stacked structure in which second insulating layers and second conductive layers are alternately stacked; a first memory pillar provided in the first stacked structure; a first dividing structure dividing the first conductive layers; a second memory pillar provided within the second stacked structure and connected to the first memory pillar; a second dividing structure dividing the second conductive layers; a first alignment mark pillar provided in the first stacked structure and projecting from the first stacked structure; a second alignment mark pillar provided on the first alignment mark pillar; an alignment mark surrounded by the second alignment mark pillar.