摘要 |
A pattern test device has a reference data generator (13) for generating reference pattern data and setting a first sub-area or a second sub-area in a mask area depending on the accuracy for the pattern test. A threshold selecting section (18) selects first or second threshold depending on the test location residing in the first sub-area or second sub-area, whereby the judgement section (16) judges presence or absence of a defect in the mask area while using the first or second threshold to compare therewith difference data between the test pattern data and the reference pattern data. <IMAGE> |