US Patent 7567422 Plasma processing apparatus and plasma processing method

In the plasma processing apparatus including a processing chamber for plasma-processing a processed substrate, plasma generating unit that generates plasma in the processing chamber, and a wafer stage which is mounted in the processing chamber and has an electrostatic chuck for holding the processed substrate, a current detector that detects a current value of leakage current flowing in a circuit formed of a power supply for electrostatic attraction, an electrostatic chuck, a substrate, plasma, a grounded line, and a controlling unit which sets an attraction condition to the current value and controls the applied voltage so that the leakage current reaches the set current value are included.