A method capable of stirring a liquid sample and a reagent promptly and easily includes the following steps (A) and (B). In step (A), using a cell including: a liquid sample retaining section having a plurality of particles; and a liquid sample supply inlet, a liquid sample containing an analyte is supplied from the liquid sample supply inlet to the liquid sample retaining section. In step (B), the liquid sample and a specific binding substance capable of specifically binding to the analyte are stirred by the movement of the particles caused by the flow of the liquid sample in the cell resulting from the supply of the liquid sample, to obtain a liquid mixture. The electric charge of at least the surface of the particles and the electric charge of the specific binding substance have the same polarity in the liquid mixture.