Provided is a liquid crystal display device that has a wide reproduced color gamut without noticeable color unevenness even if it is an image display device that shows an steep emission spectrum in the red region, in particular, even if it comprises a light source having a steep emission spectrum in the red region, such as a KSF phosphor, as a backlight light source. The image display device comprises an image display cell and at least one polarizer, wherein the at least one polarizer is a polarizer in which light incident on the polarizer has a plurality of peak groups in the range of 600 to 650 nm, and the at least one polarizer comprises a polarizing element-protection film having a 45-degree light source fit index (FI(45)) of 0.4 or more and 0.62 or less as determined by the following formula 1:

FI(45)=Wd/[Wc/(Rob(45)/Wc)]  formula 1.