A region divided substrate includes a substrate, a plurality of trenches, a conductive layer, and an insulating member. The substrate has a first surface and a second surface opposed to each other. The trenches penetrate the substrate from the first surface to the second surface and divide the substrate into a plurality of partial regions. The conductive layer is disposed on a sidewall of each of the trenches from a portion adjacent to the first surface to a portion adjacent to the second surface. The conductive layer has an electric conductivity higher than an electric conductivity of the substrate. The insulating member fills each of the trenches through the conductive layer.