Plasma processing apparatus and plasma processing method

A plasma processing method comprising:

• generating a plasma in a chamber of a plasma processing apparatus, the plasma processing apparatus including the chamber, a substrate support provided in the chamber and including a first region on which a substrate is placed and a second region which surrounds the first region and on which an edge ring is placed, a plasma generator configured to generate a plasma in the chamber, at least one electromagnet configured to generate a magnetic field localized in an annular space above the edge ring, and a power source electrically connected to the at least one electromagnet and configured to adjust a strength of the magnetic field;
• and
• generating, when the plasma is being generated, the magnetic field having the strength adjusted according to a thickness of the edge ring.