A polarizing plate comprises a polarizing element; and a hydrophilic polymer film adhered on the polarizing element and having an in-plane orientation. The transmittance of the polarizing plate as a single unit for light having a wavelength of 590 nm is 40% or more under an environment of 23.degree. C. and 55% RH, the crossed-Nichols transmittance T2 of the polarizing plate is 0.03% or less under an environment of 23.degree. C. and 55% RH, and a change .DELTA.T2 in the transmittance T2 of the polarizing plate when the relative humidity changes from 20% RH to 80% RH at 23.degree. C. satisfies the following formula: 0.05.times.T2<.DELTA.T2<0.9.times.T2.