PURPOSE: To release a coating film in a short time and effectively use spent fats and oils by incorporating an ester compound composed of a specific fatty acid molecule and a specific alcohol molecule as an effective component.

CONSTITUTION: An ester compound composed of one 4-18C fatty acid molecule and one 18 or less C alcohol molecule and dissolved or emulsified in water is incorporated as an effective component. The ester compound is, for example, an n-methyl caproate, a methyl laurate, a methyl oleate, a methyl benzoate, an ethyl benzoate, an n-amyl benzoate, and a phenyl benzoate. It is preferable that the loadings of the ester compound be not less than 1wt.%, esp. not less than 5wt.%, of a coating film releasant composition liquid. In this manner, a coating film can be released in a short time, and spent fats and oils can effectively be used.