Disclosed is an adhesive composition which is mainly composed of a polymer obtained by copolymerizing a monomer composition containing styrene, (meth)acrylic acid ester having a cyclic structure and alkyl (meth)acrylate having a chain structure. The monomer composition may additionally contain a bifunctional monomer, thereby improving heat resistance, adhesive strength under high temperature conditions, and alkali resistance, and easiness in stripping of an adhesive composition that has been processed at a high temperature. Consequently, there can be obtained an adhesive composition which has high heat resistance, adhesion strength under high temperature conditions, and alkali resistance, and which can be easily stripped off after the adhesive composition is processed at a high temperature.