Provided is an example of a technology capable of accurately controlling impedance.
Provided is a substrate including a first through hole that penetrates a substrate from a first face to a second face of the substrate, and is electrically connected to a transmission line through which a signal is transmitted, a second through hole that is provided adjacent to the first through hole in plan view of the substrate, penetrates the substrate from the first face to the second face, and is electrically connected to a ground, and an adjustment unit that adjusts a distance between the first through hole and the second through hole in plan view of the substrate to adjust an impedance of a connection end of the first through hole with the transmission line.