The inventive concept provides a substrate treating apparatus. The substrate treating apparatus includes a process chamber having a treating space therein; a support unit for supporting a substrate within the process chamber; a gas supply unit for supplying a process gas inside the process chamber; and a plasma generation unit for generating a plasma from the process gas, wherein the plasma generation unit comprises: a top electrode disposed above the substrate; a bottom electrode disposed below the substrate; an edge electrode disposed at an edge surrounding the substrate; three high frequency power sources applying a high frequency power to the bottom electrode; and an edge impedance control circuit connecting to the edge electrode.