PURPOSE: To provide an apparatus for inspecting the surface by irradiating the surface with an inspecting light and receiving the reflected light in which fluctuation in the inspection sensitivity and the image size is suppressed even for a curved surface while facilitating the teaching of movement for a robot.

CONSTITUTION: The surface inspection system comprises a light source 4 for irradiating a surface to be inspected with an inspection light having luminance or wavelength varying gradually along one direction, an image pickup means 6 for receiving the light reflected on the surface 2 to form an image, an image processing means 8 for processing the received image and inspecting the state of the surface 2 based on the variation in the luminance or wavelength, and a half mirror 14. The light source 4, the image pickup means 6 and the half mirror 14 are arranged so that the optical axis 4a of the light source 4 with respect to the surface 2 through the half mirror 14 is aligned with the optical axis 6a of the image pickup means 6.