In the present work,a simply designed and easy made micrometer plasma jet device operating under atmospheric pressure was characterized.The microplasma jet operates in many kinds of working gas at atmospheric pressure,such as Ar,He,N 2 etc,and is powered by a direct current power source.It can generate high current density glow discharge.In order to identify various excited species generated by the direct current microplasma jet device,the optical emission spectra of the jet with argon or nitrogen as workin...