A semiconductor device of an embodiment includes a semiconductor layer, a first conductor, a first conductive layer, a first insulating layer, a second conductive layer, and a plurality of second conductors. The semiconductor layer has a first region and a second region. The first conductor is provided in the semiconductor layer. The first conductive layer is electrically connected to the first conductor. The first insulating layer is provided in the semiconductor layer with at least part of the first insulating layer being provided between the first conductive layer and the semiconductor layer. A distance from the first insulating layer to the first region is smaller than a distance to the second region. A first distance to the first region from a plane that includes a first interface between the first insulating layer and the first conductive layer is larger than a second distance from the plane to the second region.