Abstract: An imaging element includes: a pixel board including a light receiver including plural pixels, each pixel being configured to generate an imaging signal; a circuit board including a functional circuit, the pixel board being layered on the circuit board; plural wiring portions configured to electrically connect the pixel board and the circuit board to each other and electrically transmit signals between respective layers; a terminal provided on the circuit board, the terminal being electrically connected to each of the plural wiring portions, the terminal being configured to output the imaging signal to an outside of the terminal or receive an external signal from the outside of the terminal; and a switch configured to output, by selective switching, at least one of the imaging signal and an internal signal generated at the circuit board, to the terminal.