Abstract: Provided is a semiconductor device having a high degree of integration, which includes first and second transistors and a first insulating layer. The first transistor includes a first semiconductor layer, a second insulating layer, and first to third conductive layers. The second transistor includes a second semiconductor layer, a third insulating layer, and fourth to sixth conductive layers. The first insulating layer includes a region in contact with the first semiconductor layer and the first conductive layer and includes an opening reaching the first conductive layer. The first semiconductor layer is in contact with a top surface of the first conductive layer, an inner wall of the opening, and the second conductive layer. The second conductive layer is positioned over the first insulating layer. The third conductive layer is positioned over the first semiconductor layer and includes a region overlapping with the inner wall of the opening with the second insulating layer positioned therebetween.