An object identification method capable of quickly and accurately identifying a virus or the like is provided. An object identification method according to an aspect of the present disclosure includes feeding an object dispersed in a solvent to a micro-channel, and applying an AC (Alternating Current) voltage to a measurement electrode provided at the micro-channel and measuring an AC characteristic of the object when the object passes through the micro-channel. Then, a combined impedance and a phase are determined by using the measured AC characteristic, and the object is identified by using the determined combined impedance and the phase.