A preparation element set including an image sensor including a sensor surface, a sensor back surface, and a board; a package including a front surface, a back surface, and terminals on the back surface, the front surface touching or facing the sensor back surface; and a transparent plate facing the sensor surface with a subject placed therebetween, wherein the board includes a board surface and a board back surface, a distance between the board surface and the sensor surface is less than a distance between the board back surface and the sensor surface, a distance between the board surface and the sensor back surface is more than a distance between the board back surface and the sensor back surface, conductive holes pierce the board from the board surface to the board back surface, and conductors on the board surface are electrically connected to terminals by using the conductive holes.