There is provided a composition that can effectively remove a protective coating and a primer coating that have a resistance to etching solutions and are rendered unnecessary after wet-etching treatment in MEMS fabrication processes, and a method for removing the protective layer. The composition contains (A) at least one organic solvent selected from the group consisting of amides, lactones, pyrrolidones and ketones, (B) water, and (C) a fluoride, in an amount of 80.00 to 99.90 mass %, 0.05 to 12.00 mass %, and 0.05 to 8.00 mass %, respectively. The composition may further contain (D) phosphoric acid, phosphonic acid or phosphinic acid in an amount over 0 mass part to 5.5 mass parts, or (E) an organic amine in an amount over 0 mass part to 45 mass parts, based on 100 mass parts of the composition.