A protective coat layer-forming composition is used for forming a protective coat layer of a protective coat layer-laminated film including a base film made of a cyclic olefin resin and the protective coat layer formed on at least one side of the base film. The protective coat layer-forming composition includes a component (A) of a multifunctional acrylate monomer, a component (C) of an isocyanuric acid derivative having two or more (meth)acryloxy groups, a component (D) of a caprolactone oligomer derivative having three or more (meth)acryloxy groups, and a component (E) of a photopolymerization initiator.