CALCULATION METHOD AND CALCULATION APPARATUS

The present invention provides a method of calculating a surface shape of a target surface, including the steps of defining, as a measurement target region, each of a plurality of regions on the target surface in which adjacent regions overlap each other, and obtaining data that give the heights at the plurality of positions in each of the plurality of regions, and removing, for each of the plurality of regions, an average data from the data that are obtained in the step of obtaining the data and give the heights at the plurality of positions in each of the plurality of regions, thereby generating correction data for each of the plurality of regions.