Liquid crystal display device, polarization plate, and polarizer protective film

Provided is a polarizer protective film comprising a polyester film which is capable of inhibiting the leakage of light, even in cases when two polarization plates are disposed in a crossed Nicols state. This polarizer protective film comprises a polyester film. The absolute value of the gradient of the thermal shrinkage of said polyester film in a film flow direction or width direction is not more than 15˚.