PURPOSE: To obtain such a film that has extremely high flexibility although it has enough hardness, and therefore, it does not generate cracks even when it is bent to a certain degree.

CONSTITUTION: This protective film 10 for a polarizing plate consists of a cover film 1 comprising triacetylcellulose and a protective layer 2 formed on the film 1. The protective film contains a urethane polymer of a compd. expressed by formula and an acrylate having two or more functional groups in the molecule including a hydroxyl group which reacts with the isocyanate group of the compd. This polymer is hardened with UV rays. In formula, A is a chain structure having >4 atoms in the main chain and containing carbon atoms, and X, Y are -NCO, hydrogen atoms or hydrocarbon groups.