Abstract: A defect inspection apparatus includes a first unit, a second unit, and a third unit which respectively irradiate first, second, and third inspection lights to the sample holder, a camera including a single image sensor which generates an image of a sample, which moves linearly on the sample holder, using time delay integration, and a detector which detects defects of the sample based on an image provided by the camera, where the first, second, and the third inspection lights are simultaneously irradiated to the sample holder, and where the single image sensor includes first, second, and third sections, the first section which generates an image of the sample taken by the first inspection light, the second section which generates an image of the sample taken by the second inspection light, and the third section which generates an image of the sample taken by the third inspection light.