There is provided an X-ray diffraction apparatus comprising an X-ray topography device for providing a spatial geometric correspondence to an X-ray exiting from a planar region of a sample to detect the X-ray as a planar X-ray topograph, and outputting the X-ray topograph as a signal; a two-dimensional imaging device for receiving a light-image of the planar region of the sample and outputting the light-image as a signal specified by planar positional information; and a video-synthesizing arithmetic control device for generating synthesized video data on the basis of an output signal from the X-ray topograph and an output signal from the imaging device.