Method of etching treatment

An etching treatment method which is performed, by use of an etching apparatus which has a vacuum chamber which is evacuated to produce a vacuum by vacuum evacuation means, etching gas introducing means for introducing an etching gas into the vacuum chamber, means for setting a sample to be worked which is provided within the vacuum chamber and sets the sample to be worked, cooling gas introducing means which supplies a cooling gas to a back surface of the sample to be worked, a high frequency power source of high frequency electromagnetic waves supplied into the vacuum chamber, a matching device, power introducing means which introduces high frequency power into the vacuum chamber, and a high frequency bias power source which applies a high frequency bias voltage to the sample to be worked, by converting a gas introduced into the vacuum chamber by the etching gas introducing means into a plasma by high frequency power which is introduced by use of the power introducing means and applying high frequency bias power to the sample to be worked, whereby surface treatment of the sample to be worked is performed by the plasma,

• wherein in treating the sample to be worked by use of a highly depositable gas, the temperature of the sample to be worked at the start of the treatment is maintained at a desired level.