In one embodiment, an electronic device includes first and second substrates, an insulating layer, and a connecting material. The first substrate includes a first conductive layer. The second substrate includes a basement having first and second surfaces, a second conductive layer on the second surface, and a first hole penetrating through the basement. The insulating layer is arranged between the first conductive layer and the basement, and has a second hole. The connecting material connects conductive layers via holes. The first hole has a first opening on a first surface side. The second hole has a third opening on a first conductive layer side which is larger than the first opening.