An affinity particle, characterized in that it comprises an inorganic particle, a phosphoryl coline group represented by the following formula (1) bound to the surface of the particle by a covalent bonding, and a ligand having the specific affinity to an objective material bound to the particle by a covalent bonding or adsorption. An affinity separation method using the above affinity particle utilizes inorganic particles being produced at a low cost and allows the separation of an objective material with simplicity and ease and with high accuracy.
