PURPOSE: To accurately observe deterioration and change of tissue non- destructively irrespective of that a surface to be observed is flat or curved by transferring the surface of a steel material to be observed to a replica film and carrying out gold-deposition on its transferred surface.

CONSTITUTION: First, a replica film 4 is press-bonded to the surface to be observed, and a precipitate 6, a creep void 7, etc., are transferred, and extracted. Then, the film 4 surface is gold-deposited 11 at about 300-500. This is laminated to a base plate 8, and the surface of the film 4 which is gold-deposited 11 is irradiated with laser light 10 through a lens 9 of a laser microscope. A laser light 10 is reflected by the deposited gold 11, and can be observed through the lens 9. Thus, a curved surface or a component which cannot be cut out can be easily and accurately observed non-destructively with a laser microscope for change of precipitate, a distribution of creep void, etc., which need high magnification observation.