A fabric protectant which is an ester compound given by formula (1): ##STR00001## wherein R.sup.1 represents a hydrogen atom, methyl group, methoxy group or methoxymethyl group, and R.sup.2 and R.sup.3 independently represent a chlorine atom, hydrogen atom or methyl group, and 2,4,6-triisopropyl-1,3,5-trioxane are enveloped in a film selected from the group consisting of polyethylene having 0.91 to 0.94 g/cm.sup.3 of density, copolymer of ethylene and vinyl acetate, and copolymer of ethylene and methyl metacrylate is useful for controlling insects which are harmful to fabric and protecting fabric from the insects.