A semiconductor device of the present disclosure includes: a semiconductor element disposed on a first surface side of a semiconductor substrate; a through-electrode that is provided through the semiconductor substrate in a thickness direction of the semiconductor substrate and introduces charge obtained in the semiconductor element to a second surface side of the semiconductor substrate; and an amplifier transistor that outputs an electrical signal based on the charge introduced by the through-electrode, the amplifier transistor using the through-electrode as a gate electrode and including a source region and a drain region around the through-electrode.