Provided are mixed ligand metal nanoparticle chemical sensors in which metal nanoparticles are encapsulated by at least two kinds of different molecule ligands having a relatively low conductivity and various composition ratios, and a chemical sensor array in which a film of the metal nanoparticle sensor is formed on the substrate. The metal nanoparticle sensor using the mixed ligand improves sensitivity and reaction speed with respect to an analyte, and selectivity with respect to various analytes, and a kind and a composition of a ligand of the mixed ligand constituting the metal nanoparticle sensor are adjusted to allow the high sensitivity nanoparticle sensor to be applied to the sensor array technology, thereby enabling a design of sensor properties as well as systematic access to a configuration of the sensor array the most efficient for the analytes.