An image processing method includes a step of acquiring a measured image G1B measured from a semiconductor device S and a first pattern image G2B showing a pattern of the semiconductor device S, a step of acquiring a reference measured image G3B measured from a reference semiconductor device SR being the semiconductor device S or a semiconductor device different from the semiconductor device S and a second pattern image G4B showing a pattern of the reference semiconductor device SR, a step of acquiring matching information indicating a correlation of the first pattern image G2B and the second pattern image G4B, and a step of determining a difference of the measured image G1B and the reference measured image G3B based on the matching information to acquire a comparative image G5B.