To provide a method for obtaining a plastic film which gives an optical member having few optical defects when it is used particularly in optical applications and permits improvement in the productivity and to provide a laminate using the plastic film obtained by the method.

The preservation method comprises preserving the plastic film in a sealed container which has 0 piece of a stuck dust having a particle size of at least 50 μm and at most 2,000 pieces of the stuck dust having a particle size of at least 5 μm but less than 50 μm per m2 of the inner surface thereof. The laminate has a thin film layer on at least one surface of the plastic film preserved by the method.