The electronic structure of protonic conductor SrZr1-xMxO3-delta (M = Y3+, Sc3+) has been studied by soft-X-ray spectroscopy. The valence band is mainly composed of O 2p state. The conduction band is composed of Zr 4d state. The holes and the acceptor level are observed at the top of valence band and just above the Fermi level (E-F), respectively. In H-2-annealed SrZr1-xMxO3-delta (M = Y3+, Sc3+), their intensities A decrease and the hydrogen-induced level is created at just below EF. The energy separation between the bottom of the hydrogen-induced level and the top of valence band agrees with the activation energy estimated from the electrical conductivity. (c) 2005 Elsevier B.V. All rights reserved.