The substrate processing apparatus includes a process chamber providing a space for processing a substrate, a chuck member provided in the process chamber and supporting the substrate, a ring member provided to surround the chuck member, an edge electrode disposed in the ring member to be electrically insulated from the chuck member, an edge impedance controller electrically connected to the edge electrode and controlling an electric potential of the edge electrode, and a coupling compensator connected between the chuck member and the edge electrode and provided to cancel or adjust coupling between the chuck member and the edge electrode.