An optical disc includes a processed area that has been processed by the irradiation of a YAG laser. Concave pits and convex pits having a length 3T-14T (T=0.133 m) are formed in an area of the optical disc other than the processed area. The processed area includes (1) a concave pit having a length X or (2) a pit string that has a length X and includes a convex pit from which a reflection layer has been removed. A specific area of the optical disc records physical character information that shows the location and length of the concave pit or the pit string in the processed area.