According to one embodiment, a semiconductor device includes a first semiconductor circuit layer including a first conductive layer, a second semiconductor circuit layer including a second conductive layer, and a third semiconductor circuit layer between the first semiconductor circuit layer and the second semiconductor circuit layer, the third semiconductor circuit layer including a third conductive layer in contact with the first conductive layer, a fourth conductive layer in contact with the second conductive layer, and a fifth conductive layer in contact with the third conductive layer and electrically connected to the fourth conductive layer. The fifth conductive layer has a width that is narrower than a width of the third conductive layer.