A microwave plasma processing system, wherein a conductor disposed for controlling the anisotropy and the acceleration energy of ions in a plasma has inside a flow path for reactant gasses and a plurality of holes through which the gasses are to be blown toward a sample holder. A microwave plasma processing system, wherein the ratio of the total area of microwave transmission holes to the area of a conductor is set to be in a range of 0.25 to 0.65. A microwave plasma processing system, wherein each microwave transmission hole formed in a conductor has a dimension in the microwave traveling direction greater than that in a direction perpendicular to the traveling direction. <IMAGE>
