PURPOSE: To perform an anisotropic plasma etching operation and an isotropic plasma etching operation in a mixed manner without changing a plasma parameter such as the kind of a reaction gas, the pressure of a gas or the like and to prevent a semiconductor substrate form being contaminated due to a wet etching operation in the plasma etching apparatus of the semiconductor substrate.

CONSTITUTION: The title apparatus is composed of the following: a power-supply part 9 which generates a plasma; and a reaction part which causes a reaction with a material to be etched (a substrate 1). A magnetic-force source 12 which generates a magnetic field is arranged at the outside and the inside in such a way that a magnetic field B is formed in the horizontal direction of the material to be etched (the substrate) in the reaction part.