There is disclosed a plasma technique in which a plasma generation
technique frequently used in various fields including a semiconductor
manufacturing process is used, and generation of plasma instability
(high-speed impedance change of a plasma) can efficiently be suppressed
and controlled in order to manufacture stable products. In a method of
disposing an object in a chamber and generating the plasma to treat the
object, the chamber is sealed by a surrounding member so as to have an
inner space, at least a part of the member includes a dielectric
material, an RF induction coil is disposed outside the dielectric member,
and a direct-current electric field is supplied into the inner space by a
method of passing a direct current through the RF induction coil or
another method, so that the plasma is stabilized.