The pressure-sensitive adhesive layer for an optical film having good heat and moisture durability is formed by a process of applying an aqueous dispersion-type pressure-sensitive adhesive containing an emulsion of a (meth)acryl-based polymer obtained by subjecting a monomer mixture containing at least one of an alkyl (meth)acrylate (a1) with an alkyl group of 1 to 3 carbon atoms and an alkoxysilyl group-containing monomer (a2), and an alkyl (meth)acrylate (b) with an alkyl group of 4 to 14 carbon atoms to emulsion polymerization in water in the presence of a radical polymerization initiator and a reactive surfactant having a radically-polymerizable functional group; and then drying the emulsion, wherein a content of the reactive surfactant is 0.3 to 3 parts by weight based on 100 parts by weight of the monomer mixture, and has a saturated water absorption of 1.2 to 3.2% by weight at 50° C. and 90% R.H.