The present invention relates to a method for manufacturing an ester from a ketone or an aldehyde, which is a reactive substrate, by a Baeyer-Villiger oxidation reaction using hydrogen peroxide, and in this method, as a catalyst, M(BAr4)n, which is a metal borate, is used (M represents an alkali metal or an alkaline earth metal; Ar represents an aryl; and n is the same number as the valence of M). For example, when cyclohexanone was used as the reactive substrate, and Sr[B(3,5-CF3C6H3)4]2 was used as the catalyst, ε-caprolactone was obtained at an isolated yield of 82%.