A resolution-variable X-ray imaging device is provided and includes: a scintillator that receives an X-ray through a subject to emit fluorescence; and an imaging device comprising a plurality of pixels aligned at pixel intervals on a light receiving surface of the imaging device, each of the pixels receiving the fluorescence and converting the fluorescence into an electric signal. The imaging device has at least two areas of: a higher-resolution imaging area in which the pixels are aligned at a pixel interval; and a lower-resolution imaging area in which the pixels are aligned at a pixel interval longer than the pixel interval of the higher-resolution imaging area.