Structural member

Abstract

A structural member 10 includes: a base material 100; and a protective film 200 that is a film covering a surface 110 of the base material 100 and contains polycrystalline yttria as a main component. When an average value calculated from the particle diameters of crystal particles CP of yttria appearing in a cross-section given by slicing the protective film 200 along a plane parallel to a surface 110 of the base material 100 with weighting by the cross-sectional areas of the crystal particles CP is defined as an average diameter, and a part of the protective film 200 proximity to a surface 210 of the protective film 200 opposite to the base material 100 is defined as a shallow part 201, the average diameter in the shallow part is 80 nm or more.

Dependencies are inferred from the claim text.