PROBLEM TO BE SOLVED: To provide an adhesive layer having both of high adhesive force and high adhesiveness even in a thin film state having 1 micro m to 20 micro m, and an adhesive film using the adhesive layer.SOLUTION: The adhesive layer is formed by crosslinking an adhesive composition comprising an acrylic polymer. The acrylic polymer is a copolymer that comprises: at least one alkyl (meth)acrylate monomer having 1 to 14 carbon atoms in an alkyl group; at least one (meth)acrylate monomer having an aromatic group; and as other copolymerizable monomers, at least one vinyl monomer having a nitrogen atom and at least one copolymerizable vinyl monomer having a hydroxyl group. A crosslinking agent is used, which is a tri-functional isocyanate compound. The adhesive layer has a thickness of 1 micro m to 20 micro m; and the adhesive layer having a thickness of 20 micro m thick exhibits...
