A plasma etching method using a Faraday cage, including: providing an etch substrate in a Faraday cage, where the etch substrate includes a metal mask provided on one surface thereof, and where an upper surface of the Faraday cage is provided with a mesh portion; a first patterning step of forming a first pattern area on the etch substrate; and a second patterning step of forming a second pattern area on the etch substrate after shielding at least a part of the mesh portion with a shutter. The first pattern area includes a first groove pattern having a depth gradient of 0 to 40 nm per 5 mm, and the second pattern area includes a second groove pattern having a depth gradient of 50 to 300 nm per 5 mm.