Evaluation of the elastic scattering effect in electron spectroscopies, i.e. XPS, AES, EPES etc., is important for the quantitative surface analysis. We classify the elastic scattering effects and emphasize the importance of a choice of the elastic-scattering differential-cross-sections based on Rutherford scattering, Thomas-Fermi-Dirac potential, and Dirac-Hartree-Fock potential for the detailed estimation of the elastic scattering effects. We also mention of the simple way to deal with the average practical effective attenuation length (average PEAL) including elastic scattering effects and demonstrate this average PEAL is useful for the analysis of angle-resolved high-energy XPS.