PURPOSE:To make it possible to manufacture a low-cost optical card without using a high-cost optical recording material wastefully by using a roughed surface original plate with a pattern in units of an optical recording material part arranged finely. CONSTITUTION:A roughed surface original plate with a low reflective part having a roughed surface in accordance with an information recording pattern is prepared by arranging finely a pattern of a size equal to the unit of an optical recording material part. The optical recording medium with this information recording pattern formed is used as a surface roughed original plate 15, and a mother mask is duplicated based on the original plate 15 using a die-punching press. Next, the original plate 15 is parted from a transparent base 21 to duplicate a pattern on the base 21 side and thereby form a mother mask 23. After that, the mask 23 is used as a duplication original plate for mass-duplication and a base 101 of duplication resin 31 is duplicated by die-punching. Further, film 100a is peeled off and the base 101 is parted from the mask 23 to duplicate a pattern. Thus a low reflective rate part is formed on the surface of the resin 31 and the resin 31 becomes the base 101 of an optical card.