The process for producing a glass mold according to the present invention comprises forming, on a glass mold base, a thin film consisting of diamond crystallites, graphite crystallites and amorphous carbon and having a maximum surface roughness of 200 .ANG. or below, by a plasma CVD method or a thermal CVD method using a mixed gas comprising an organic gas and hydrogen gas, the concentration of the organic gas in the mixed gas being at least 3 mole %.The glass mold obtained according to the present process has advantages of having excellent releasability of molded glass article after press molding, excellent durability and a long life.