An alignment method includes a step of measuring the positions of a plurality of sample shot areas, a step of calculating conversion parameters between the measured positions of the sample shot areas and designed positions thereof so as to minimize the overall error of all of the measured positions, a step of selecting one or more sample shot areas, a step of memorizing the conversion parameters calculated in correspondence with the combinations of the sample shot areas; and a step of determining whether or not to finish the alignment measurement on the basis of the conversion parameters memorized in correspondence with the combinations of the sample shot areas.