To provide a release agent composition which is prepared by using a nonhalogenous organic solvent superior, in terms of environmental load or safeness, to a halogenous organic solvent and which dries quickly, can form a thin film, and has high release characteristics.

This release agent composition, used e.g. for a gypsum model, comprises (a) an ionic surfactant, preferably at least one ionic surfactant selected from among sulfuric ester salts, sulfonic acid salts, and quaternary ammonium salts, (b) water, and (c) a water-soluble volatile nonhalogenous organic solvent.