NOVELTY - The apparatus has a high frequency antenna (11) that generates inductively coupled plasma to a plasma production region. A metal window is positioned between the plasma production region and the high frequency antenna. The metal window is comprised by metal windows (30a-30d) mutually insulated by an insulator and ground-connected by grounding point. One grounding point is provided in the approximate center of the edge of each outer peripheral side or inner peripheral side of the metal window.    USE - Inductive coupling type plasma processing apparatus used for plasma-processing substrate such as glass substrate used for flat panel display such as LCD device(claimed).Uses include but are not limited to Electro luminescent display device, plasma display device and solar cell panel.    ADVANTAGE - The metal window is positioned between the high frequency antenna and the plasma production region, and ground connection of each metal window is carried out. The window electric potential of the metal window is lowered so that the occurrence of the sputter cut-out of the metal window by the plasma is suppressed, without lowering the source efficiency. The strength of the plasma is adjusted. By ground-connecting the metal window by two grounding points, the magnitude of the electrical eddy current flowing through the lower surface of the metal window is adjusted, and the strength of the plasma in the plasma production region corresponding to two grounding points is adjusted. The electrical eddy current flowing between the connection positions of the capacitor is increased by forming an electric current loop circuit, while connecting the adjoining metal windows through the capacitor. The plasma in the corresponding plasma production region is strengthened. The distribution of the strength of the plasma is controlled and homogenization of the plasma processing with respect to the substrate is attained. The plasma processing of the substrate with greater than 1 m in length is acquired.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a plasma distribution adjustment method.    DESCRIPTION OF DRAWING(S) - The drawing shows a top view of the metal window and ground connection portion of the plasma processing apparatus. (Drawing includes non-English language text)    Side wall of antenna chamber (4a)    Support cross-beam (7)    High frequency antenna (11)    Metal windows (30a-30d)    Ground connection portion (50)