Abstract: There exist a pattern-dense region where patterns having an F-letter shape are dense and a pattern-interspersed region where small rectangular dummy patterns are interspersed. In the pattern-interspersed region, the dummy patterns are arranged in a manner that at least one dummy pattern exists in a scan target range of a mask pattern defect inspecting apparatus. With the dummy patterns formed in the pattern-interspersed region at the intervals as described above, when one scan target range is scanned by the mask pattern defect inspecting apparatus, at least one dummy pattern is included in the scan target range in the pattern-interspersed region. Therefore, mix-up of alignment in this range is prevented from occurring, which makes it possible to perform proper defect inspection.