A member for a plasma processing unit and a plasma processing device having the same

The members for the plasma treatment apparatus of the present disclosure include a substrate and a membrane of oxides, fluorides, wildfires or nitrides of rare earth elements in at least a portion of the substrate. The film has a ratio σ22 / σ11 of compressive stress σ11 occurring within the surface exposed to the plasma of the film and a compressive stress σ22 occurring in a direction perpendicular to the compressive stress σ11 within the surface is 5 or less. The plasma processing apparatus of the present disclosure includes a member for the plasma processing apparatus above.