PROBLEM TO BE SOLVED: To provide a phase image processing method for simply generating a phase image with high accuracy.SOLUTION: The phase image processing method includes a step for generating a differential image in a first direction on the basis of image information of a subject, and a step for generating the differential image in the first direction, and a phase image on the basis of the difference of a signal value between pixels arranged in a second direction being a direction different from the first direction in the differential image in the first direction.SELECTED DRAWING: Figure 2COPYRIGHT: (C)2017,JPO&INPIT