1. An inspection method comprising: setting a measurement area on a board; acquiring reference data and measurement data of the measurement area; establishing a plurality of feature blocks by a block unit so as to include a predetermined shape in the measurement area; establishing a merged block by merging feature blocks overlapped in the feature blocks; acquiring a distortion degree by comparing the reference data and the measurement data corresponding to a non-merged block and/or the merged block; and compensating for the distortion degree to set an inspection area in the target measurement area, wherein establishing the plurality of feature blocks by the block unit so as to include the predetermined shape in the measurement area includes: finding a location of a corner of a bent circuit pattern corresponding to the predetermined shape; and establishing a margin area of the corner of the bent circuit pattern and establishing the feature blocks defined by the established margin area.