An adhesive for adhering a protective film, the protective film having a water vapor transmission rate of about 100 g/m2·day or less at 40° C. and about 90% RH during manufacture of an optical member including a polarizing plate, a polarizing plate including an adhesive layer prepared from the adhesive, and an optical member including the polarizing plate, the adhesive including a (meth)acrylic copolymer, the (meth)acrylic copolymer having a weight average molecular weight of about 800,000 g/mol or more; a curing agent; and a silane coupling agent, wherein an adhesive layer prepared from the adhesive has a storage modulus, after curing, of about 8×103 Pa or more at about 85° C. and a frequency of about 10−3 rad/s to about 102 rad/s.