Spectral emittance and thermal stability of two‐dimensional W surface gratings are investigated to obtain high‐temperature resistive selective emitters for TPV applications. Numerical calculations based on rigorous coupled‐wave analysis are performed to determine the structural profile of surface gratings. According to the determined parameters, W gratings composed of rectangular microcavities with the period of 1.0 &mgr;m are fabricated on single crystalline and polycrystalline W substrates by means of fast atom beam etching technique. The grating shows a strong emission peak which can be explained by the confined modes inside the cavities. The grating made from a single crystalline W shows very high thermal stability up to 1400K, while the polycrystalline grating is deformed at a high temperature because of the grain growth. © 2003 American Institute of Physics