It is an object of the invention to secure a large area of a photodiode and suppress operation property variation and malfunction in an imaging panel and an X-ray imaging device. An imaging panel (10) includes a substrate (40), a TFT (14), an interlayer insulating film (44), a metal layer (45), and a photodiode (15). A data line (12) and the photodiode (15) face each other in a thickness direction of the substrate. The interlayer insulating film (44), which is disposed between the TFT (14) and the photodiode (15), is an SOG film or a photosensitive resin film.