In order to study the feasibility of submicron lithography using second harmonic light of a copper vapor laser(CVL), a 1∶1 catadioptric projection lens, and an illumination system which consists of a rotating diffuser and a ligth pipe, are designed and constructed. A resolution of 0.6 μm line/space patterns is produced in AZ1350 resist. The result shows that the second harmonic light of CVL can be used as an illumination source in submicron lithography.