Method and equipment for detecting pattern defect

An inspection apparatus comprising:

• a light source which emits an ultraviolet laser beam;
• an illuminating unit which sequentially illuminates a plurality of points along a specimen with light emitted from the light source by shifting the ultraviolet laser beam periodically;
• a detection unit having a storage-type detector which detects an image at each point by accumulating detected light within a specified period of time from each of the plurality of points which have been periodically illuminated sequentially along the specimen to obtain detected images and further performs the summation of each detected image on the storage-type detector to acquire a summation image containing each of the plurality of detected points on the specimen;
• and
• a processor which detects a defect on the specimen by comparing the detected acquired summation image obtained by the detection unit with a reference image.