An inspection device includes a first processor, a second processor, and a server. The first processor detects first coordinates of first feature points from first images in a first image set. The second processor detects second coordinates of second feature points from second images in a second image set. The server generates reference coordinates based on the first coordinates and the second coordinates. The reference coordinates are transmitted to the first processor and the second processor. The first and second image sets correspond to scanned swaths on a wafer.