PURPOSE: To be kept without spoiling the appearance quality even when the coated film is peeled off, by incorporating natural rubber, carbon black and sulfur in a specified ratio.

CONSTITUTION: The compound is obtained by compounding 35-60wt.% natural rubber, 15-50wt.% carbon black having ≤1μm particle size, 15-50wt.% sulfur and, if necessary, a vulcanization accelerator such as tetramethylthiuram disulfide, a vulcanization accelerator auxiliary such as zinc oxide, and a filler such as phenol resin, or the like. Next the compound is kneaded and then is pressed at 140-170°C for 5-60min to cure and mold and produce the solid lubricating release agent consisting of the vulcanized rubber. If necessary, the release agent is applied to a glass press-molding die to mold glass, etc.