1. An image reading apparatus comprising: a scan quality parameter extraction part that extracts a scan quality parameter representing the quality of a scanned image from image data, using a scan error detection system; a scan quality evaluation part that reads out a threshold value from a memory on the basis of a type of the scan error detection system, compares the scan quality parameter and the threshold value, and identifies a specific scanning error occurring in the image reading apparatus based upon the comparison of the scan quality parameter and the threshold value; and a notification part that notifies a user with a type of error message corresponding to the identified scanning error in the image reading apparatus.