A method for determining an analyte in a sample, includes the steps of: (a) mixing the analyte and a first specific binding substance, the first specific binding substance being a substance that can specifically bind to the analyte; (b) adding microparticles having a second specific binding substance bound thereto to a mixture obtained in the step (a) and mixing therewith, the second specific binding substance being a substance that can specifically bind to the first specific binding substance; and (c) determining an agglutination reaction of the microparticles in a mixture obtained in the step (b).