In order to inspect the substrate, first, it sets the measurement region on the substrate, and obtains the reference data and the measurement data of the measurement area. Then, setting the conversion conditions with respect to the measurement area, and obtains a conversion relationship in accordance with the distortion amount between the reference data and the measurement data. Next, the feature objects for comparison to verify whether the test that meets the conversion relationship, that the verification feature objects for a selected from a comparison feature object except for characteristic objects satisfy the conversion relation and formed on a substrate object pads meeting the conversion relationship using at least one method of verification method to verify the validity of a conversion relationship. Then, if it is determined that the conversion relationship between the effective determine the transition condition, and sets a search range according to the determined conversion conditions. Consequently, it is possible to accurately set the searching range which compensates for the distortion.