Polishing pad and polishing device

The present invention provides a polishing pad used to form a planar surface on glass, semiconductors, dielectric material/metal composites and integrated circuits, as well as a polishing apparatus where it is difficult for the surface of the substrate to be scratched, the state of polishing can be accurately measured optically during polishing, and whether or not the entire surface of the workpiece is uniformly polished can be measured. The present invention adopts the following means in order to achieve the above described objects. That is to say, the polishing pad according to the present invention is a polishing pad characterized in that a through hole for connecting the polishing surface and the rear surface is provided in such a location as to pass through the center of the wafer during polishing, the end of the through hole closer to the center of the polishing pad is at a distance of no less than 35% of the radius from the center of the polishing pad, the length of the through hole in the direction of