Defect inspection method and apparatus

A method of inspecting patterns, comprising:

• picking up a first pattern formed on a substrate to produce a first image;
• picking up a second pattern that is also formed on the substrate and corresponds to substantially a same pattern as the first pattern, thereby producing a second image;
• aligning the first image and the second image with a predetermined accuracy;
• after the first image and the second image are aligned, adjusting a brightness of at least one of the first image and the second image to substantially match a brightness of the first image with a brightness of the second image for ones of pixels of the images;
• and
• comparing the first and second images aligned and matched in brightness for ones of the pixels to detect a defect of the patterns by using information of a scattered diagram of brightness of said first and second images.