Insulation-film etching system

PROBLEM TO BE SOLVED: To provide an insulating film etching system that can effectively prevent adhesion of particles to a substrate and is excellent in performance. SOLUTION: While the substrate 9 is held by a substrate holder 2 provided in a process chamber 1, an etching gas is introduced into the chamber 1 by a gas inlet system 3. An insulating film on the surface of the substrate 9 is etched by the action of an active species and ions contained in a plasma formed by a plasma forming means 4. After completion of the etching, a control section 8 takes out the substrate 9 from the process chamber 1 by a transport robot 51 and evacuates the chamber 1 by an exhaust system. Then the section 8 removes films deposited on exposed surfaces in the chamber 1 by the action of a plasma formed by the plasma forming means 4 by introducing a cleaning gas by the gas inlet system 3. A cooling trap 12 provided at a level lower than the substrate holding surface of the substrate holder 2 is forcibly cooled and causes many fil