The present invention provides a polarizing element and a polarizing plate having improved optical characteristics and durability. A polarizing element, characterized in that it is composed of a polyvinyl alcohol resin film, the polyvinyl alcohol resin film has a degree of polymerization of 5000 to 10000, and the polyvinyl alcohol resin film adsorbs a compound selected from formula (I) , its salt and at least one dichroic dye in its transition metal complex and stretched. (In the formula, A represents a nitro group or an amino group, R1 and R2 each independently represent a hydrogen atom, a hydroxyl group, a lower alkyl group, a lower alkoxy group, a sulfo group or a lower alkoxy group with a sulfo group, and X represents whether it has Any one of benzamido with or without substituents, phenylamino with or without substituents, phenylazo with or without substituents, or naphthotriazolyl with or without substituents, the The substituent is lower alkyl, lower alkoxy, sulfo, amino or substituted amino.)