The imaging element includes, within a pixel, a semiconductor substrate, a photoelectric conversion unit formed in the semiconductor substrate, a first charge storage unit that stores a charge generated by the photoelectric conversion unit, and a first transfer gate unit formed on an opposite surface of the semiconductor substrate on an opposite side of a light incident surface and used for transfer of a charge from the photoelectric conversion unit to the first charge storage unit. The first transfer gate unit includes a first electrode embedded in a first trench formed in the semiconductor substrate from the opposite surface of the semiconductor substrate. The photoelectric conversion unit includes the first electrode, and a second electrode surrounding at least a portion of a periphery of the first electrode.