An imaging device is provided and includes a plurality of pixel parts each including a photoelectric conversion layer that generates an electric charge according to an X-ray. The plurality of pixel parts includes: a substrate including a signal output unit that outputs a signal to an outside of the imaging device according to the electric charge generated in the photoelectric conversion layer a lower electrode above the substrate and an upper electrode above the lower electrode. The photoelectric conversion layer is disposed between the lower electrode and the upper electrode. The signal output unit includes a transistor of a single-crystal semiconductor. The lower electrode includes an electrically conductive material that absorbs at least an X-ray.
