To provide a protective film for an adhesive layer which is easy to inspect contaminated foreign substances since an optical quenching state is kept despite a releasing film stuck thereon in the inspection of a polarizing plate, a phase difference polarizing plate or a retardation plate accompanied by an optical evaluation between two polarizing plates in a crossed-Nicols state, and which has characteristics free from the generation of distortions, push marks, flexures and the like on the polarizing plate, the phase difference polarizing plate or the retardation plate, in spite of various external factors in a manufacturing process, a panel bonding process and the like of the polarizing plate, the phase difference polarizing plate or the retardation plate.

The protective film for adhesive layer comprises a layer coated with a releasing agent on one side surface of a laminated film having an optically compensating film which compensates the phase differences of a biaxially oriented polyester film on one surface of the polyester film and has a thickness of 40-200 μm.