An X-ray imaging apparatus is configured to subtract a first X-ray image from a second X-ray image to generate a first subtraction image showing information on a blood vessel, calculate an amount of pixel shift between the first X-ray image and the third X-ray image, subtract the first X-ray image from the third X-ray image to generate a second subtraction image showing information on an insertion instrument, and combine the first subtraction image with the second subtraction image to generate a synthetic image by performing a pixel shift correction based on the amount of pixel shift.