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Be-rich intermetallics (beryllides) have gathered wide attentions to be adopted for high temperature environments, particularly as an advanced neutron multiplier in fusion reactors. This study reveals the valence electron structure of Be₁₂M (M = Ti, V) by using soft X-ray emission spectroscopy with ultra-high resolution (~0.22 eV). The Be-Kα spectra from the Be₁₂M phases show significantly lower densities of the occupied states near the Be-K edge than thaose of metallic beryllium. Theoretical calculations indicate that changes in the valence electron structure are derived from the large downward shift of the Fermi level in Be₁₂M, by at least 0.8 eV. Based on the knowledge of the valence electron structures and the chemical shift, chemical state mappings of BeO and Be₁₂V in the oxidized beryllide specimen were successfully obtained. The approach is applicable for visualization and identification of metallic/oxidized phase in light-element compounds by electron microscope., 軽元素ベリリウムの化学状態分布の解析に成功 --機能性エネルギー材料の開発に貢献--. 京都大学プレスリリース. 2019-03-29.