The present invention provides a Fentanyl-containing percutaneously absorbable adhesive preparation, which is obtained from economic starting materials, has a constitution simpler than that of conventional ones, has sufficient skin permeability, and which permits control of skin permeability by changing the mixing ratio of two kinds of polyisobutylene having different molecular weights, a tackifier and an organic liquid. Specifically, the present invention provides a percutaneously absorbable adhesive preparation comprising a support and an adhesive layer laminated on one surface thereof, wherein the adhesive layer comprises Fentanyl, two kinds of polyisobutylene having different molecular weights, a tackifier and an organic liquid compatible with the aforementioned two kinds of polyisobutylene and the aforementioned tackifier.