An inspection apparatus configured to be communicably connected to an image forming apparatus for printing an image on a sheet, includes a controller for receiving at least a reference image and print setting information, registering the reference image based on the print setting information, receiving a scanned image generated by reading a printed material on which an image is printed on the sheet, and inspecting the printed material based on the scanned image and the reference image corresponding to the scanned image. The controller is arranged to perform the inspection using reference data when the scanned image includes a blank page for which a corresponding reference image is not registered.