Abstract: A surface defect inspection apparatus a lighting unit shaped in an arched form laid across the path of movement of an object under inspection for illuminating its surface. A light diffusion sheet is located between the lighting unit and the path of movement of the object for forming a bright and dark light pattern on the surface of the object. A plurality of light sensors are arranged in an arched form laid across the path of movement of the object. Each of the light sensors produces an electrical signal in response to light of reflection from the surface of the object. The electrical signal is converted into an image including the bright and dark light pattern. This conversion is repeated to produce similar images in sequence for inspection of a defect which may exist on the surface of the object.