To provide a polarizer protecting film easy to produce, excellent in heat resistance, strength and moisture permeability, and having a sufficiently low photoelastic coefficient, and to provide a method for producing the polarizer protecting film.

The polarizer protecting film is based on a resin composition comprising, as essential components, a thermoplastic resin including a glutarimide unit and a (meth)acrylic ester unit, and a thermoplastic resin including a glutarimide unit, a (meth)acrylic ester unit and an aromatic vinyl unit. Since the polarizer protecting film is easy to produce, excels in heat resistance, strength and moisture permeability, and has a sufficiently low photoelastic coefficient, it is suitable for use as a polarizer protecting film.