Method of producing polymer microparticles

The invention discloses a method of producing polymer microparticles having an antigen or an antibody introduced into the surface thereof which comprises conducting miniemulsion polymerization using a monomer, a radical polymerization initiator and a hydrophobe in the coexistence of the above-described antigen or antibody to thereby produce polymer microparticles. According to this production method, it is possible to provide an immunological analysis reagent which shows a high detection sensitivity and can avoid a nonspecific reaction occurring in the existing methods.