To provide a device and a method for etching which enables individual control of parameters relating to etching performances, and thus enables optimization of etching conditions with high precision.

The etching device 1 is provided with a substrate electrode 3 for applying high-frequency power to a substrate W subjected to etching, a source electrode 5 for generating plasma (p) to be supplied above the substrate electrode 3, an electron density control means 13 for controlling the high-frequency power applied to the source electrode 5 so that an electron density Ne in the plasma (p) becomes a preset value, and an ion energy control means 15 for controlling the high-frequency power applied to the substrate electrode 3 so that an ion energy Ei in the plasma (p) becomes a preset value.