Solid solutions of bismuth-magnesium tantalates and bismuth-zinc tantalates doped with 3d-metal atoms were studied by XPS and NEXAFS. It was shown that atoms of bismuth, magnesium and zinc in all the compounds under consideration have the charge states Bi3+, Mg2+ and Zn2+, respectively, and the tantalum atoms, in turn, have an effective charge of +(5–δ).