By recording, reproducing and erasing information by using a recording thin film of the present invention, the information can be recorded, reproduced and erased by a single beam spot and new information can be rapidly rewritten while recorded information is erased. The irradiation beam is not limited to a light beam but it may be other energy beam such as electron beam or ion beam. The record medium is not limited to a disk but it may be tape or card. The present method is applicable to other recording thin film than the present thin film. The present recording thin film is applicable to other recording method than the present method. By using the present recording thin film, a manufacturing process is simple and reproducible, recording/reproducing characteristic is high and the information can be stably stored for an extended time period. The record may be rewritten a number of times.