Abstract: The invention gives a buyer of an article (gem stone) such as diamond the highest customer satisfaction by the article with such a scarcest value that there is the only article in the world to an owner. A laser output portion and the article (gem stone) are relatively positioned with respect to each other by a positioning portion 30 such that a laser beam output from the laser output portion 20 comes into a focus on an arbitrary surface of the article (gem stone) 10. On the other hand, digital image data to be marked is obtained by an image data obtaining portion 40. A laser beam control portion 50 causes the laser output portion 20 to operate according to the obtained marking data and applies a laser beam to the surface of the article (gem stone) 10 to thereby mark the digital image data on the surface of the article (gem stone) 10.