Disclosed are: a magnetic-sensitive material in which a functional substance contained therein can be separated from a mixture readily by using a magnet a magnetic-sensitive medicinal agent comprising a magnetic microparticle, an organic thin film covalently bound to the surface of the microparticle, and a medicinal agent bound and immobilized on the microparticle through the organic thin film, in which the pharmacokinetics of a medicinal agent contained therein can be controlled by using a magnet and a process for producing each of the magnetic-sensitive material and the magnetic-sensitive medicinal agent. Specifically disclosed is a magnetic-sensitive material (10) which comprises: a magnetic microparticle (1) a thin film (4) formed by a film-like compound having a second functional group, which covers the magnetic microparticle (1) a cross-linking agent (5) having a first cross-linking group and a second cross-linking group, wherein the first cross-linking group can react with the second functional group to form a covalent bond, the second cross-linking group can react with a functional group in a functional substance (6) to form a bond, and the cross-linking agent (5) is bound to the surface of the thin film (4) via a covalent bond formed by the reaction between the second functional group and the first cross-linking group and the functional substance (6) which is bound to the microparticle (1) via a bond formed by the reaction between the functional group in the functional substance (6) and the second cross-linking group.
