To provide an in-pile surface inspection device which makes it possible to obtain more detailed information by conducting surface inspections of in-pile structures automatically and displaying the conditions of the surface three- dimensionally.

This device is equipped with a distance measurement sensor group, a distance measurement processor 5, a moving device and a surface inspection processor 6. The distance measurement sensor group has a TV camera for capturing images of an object to be inspected in a refractor and measures the distance to its surface. The distance measurement processor 5 is electrically connected with the distance measurement sensor group. The moving device automatically moves it to the object. The surface inspection processor 6 detects defects on the surface of the object on the basis of the information obtained by the TV camera and has a three-dimensional geometric arithmetic unit for operating the surface of the object in a three-dimensional geometry.