The present invention relates to a nanoparticle sensor which is capable to identify an existence/nonexistence, a concentration, a size distribution and a component of the nanoparticles using an electrode pair having a separated distance of a nano-gap, in which the nanoparticle sensor includes a unit element configured with a plurality of unit electrodes electrically operated independently from each other and detects the nanoparticles based on the number of the unit electrodes electrically changed due to the nanoparticles captured into the nano-gap. The nanoparticle sensor of the present invention can detect the component, the size, the size distribution and the concentration of the nanoparticles by single measurement, have high reliability and regeneration while reducing a detection time by statistical method via a plurality of electrode pairs having the nano-gap, and detect even very low concentration of nanoparticles.