A non-aqueous secondary battery includes a positive electrode, a negative electrode, an electrolyte solution, and a separator. The positive electrode includes a current collector and a positive electrode mixed material layer formed on the current collector. The positive electrode mixed material layer contains a positive electrode active material, a conductive material, and a polymer A. The polymer A includes a nitrile group-containing monomer unit and either or both of a conjugated diene monomer unit and an alkylene structural unit. The content of the polymer A in the positive electrode mixed material layer is not less than 0.01 mass % and not more than 8 mass %. The separator includes a separator substrate and an adhesive layer formed on the separator substrate. The adhesive layer contains a polymer B and has a ratio of coverage by the polymer B of not less than 3% and not more than 70%.