Patent ID: 7138155

Claim:
A method for evaluating an optical information medium, comprising the steps of: adhering an evaluation dispersion liquid containing a fine-particle-form substance and a dispersion medium capable of dispersing the fine-particle-form substance onto the surface of the optical information medium which is on the incident side of a recording/reproducing beam; observing the state of the evaluation dispersion liquid droplets adhered to the medium surface; and judging the quality of the medium surface, wherein the fine-particle-form substance includes at least one selected from the group consisting of silica fine particles, alumina fine particles, iron oxide fine particles, keratin fine particles, chitin fine particles, chitosan fine particles, acrylic fine particles, styrene fine particles, divinylbenzene fine particles, polyamide fine particles, polyimide fine particles, polyurethane fine particles, and melamine fine particles, and/or includes Kanto loam (JIS Test Powder 1).