The present invention provides a plasma processing apparatus and a plasma processing method therefore, capable of freely and accurately controlling the plasma density distribution by using a simple correction coil. In the inductively coupled plasma processing apparatus, an inductively coupled plasma is generated in the doughnut shape below the dielectric window 52 around the RF antenna 54 and then diffused in the large processing space, so that the density of the plasma becomes uniform around the susceptor 12 (i.e., on the semiconductor wafer W), especially in radial direction. The RF antenna 54 performs an electromagnetic field correction on the generated RF magnetic field by the correction coil 70 and controls the duty ratio of the induced current flowing in the correction coil 70 by the switching mechanism 110 depending on predetermined process parameters.