An adhesive composition includes a coupling agent composed of a compound having a first functional group that reacts with an inorganic material and a second functional group that reacts with an organic material, and a crosslinking agent capable of crosslinking with a crosslinking site of a fluorine-based elastomer. A seal structure body includes a metallic support, fluorine-based elastomer and adhesive composition that causes fluorine-based elastomer to adhere to metallic support. A method for manufacturing seal structure body includes the steps of providing metallic support and fluorine-based elastomer, and causing fluorine-based elastomer to adhere to metallic support by using adhesive composition. Accordingly, an adhesive composition with high adhesion strength as well as a seal structure body and a method for manufacturing the same are provided at low cost.