Disclosed is an apparatus and method for plasma processing, which facilitates to constantly control a RF voltage supplied to a substrate supporting member by precisely detecting an inductive RF voltage induced to the substrate supporting member for a plasma, the apparatus comprising: a substrate supporting member for supporting a substrate, installed in a reaction room of a processing chamber; a RF generator for supplying a RF voltage to the substrate supporting member so as to form plasma in the reaction room; and a matching device for matching impedance of the RF voltage to be supplied to the substrate supporting member from the RF generator, wherein the matching device comprises: a matching unit for matching the impedance of RF voltage; and an inductive RF detecting unit which an inductive RF detecting voltage by removing noise frequency elements except a waveform of the RF voltage from a waveform of an inductive RF voltage induced to the substrate supporting member, and supplies the detected inductive RF detecting voltage to the RF generator so as to control the RF voltage.