To prepare the subject preparation capable of reducing the remaining amount of a volatile compound while keeping the release-controlling properties of the volatile medicine by a rosin by allowing the volatile compound to include the rosin and a glycerol ester of a fatty acid.

This sustained release preparation is obtained by allowing (A) a volatile compound comprising a volatile corrosion inhibitor or the like such as ally isothiocyanate, an antimicrobial plant-extraction oil, a spice extract, a perfume such as white-cedar leaf oil, terpenes, pyrethroids, dicyclohexylammonium nitrite and the like to include (B) a rosin and (C) a glycerol ester of a fatty acid, preferably in an proportion of 0.2-25 pt.wt. component A and 0.1-25 pts.wt. component C based on 100 pts.wt. component B.