Provided is an image analysis device for specifying an image region of an object being the basis for design similarity determination. An image analysis device 100 includes units 112, 113. The unit 112 moves original images Im1 and Im2 including a designated image region H with a rotationally symmetry on a first point P relative to a reference image Im2(j), calculates a correlation value cim(j) at each relative position, and detects the position of the point P in the images Im1, Im2, according to a geometric model, based on the amount of rotation θ(j) at which the cim(j) is the maximum and a vector v(j). The unit 113 specifies the range of the region H in the images Im1, Im2 based on the position of the point P and the distribution of the brightness values of pixels in the images Im1, Im2.