To provide a technique for simply manufacturing a press mold of high precision having an uneven pattern expressing an original mold faithfully.

A first mold 7 having a first uneven pattern 7a wherein the uneven pattern of the original mold (1) is reversed, a second mold 8 having a second uneven pattern 8a wherein the first uneven pattern is reversed by modeling the first uneven pattern of the first mold and a third mold 9 having a third unever pattern 9a wherein the second uneven pattern is reversed by modeling the second uneven pattern of the second mold are formed of FRP to obtain the press mold for mass-producing the inorganic plate. The second mold is kept and, when the third mold is used for mass production and consumed, modeling is again performed using the kept second mold to manufacture the third mold. It is preferable to manufacture the third mold by embedding a woody base material 9b such as plywood in the surface on the side opposite to the side wherein the third uneven pattern is formed.