Recently, hard X-ray photoemission spectroscopy using high-brilliance third-generation synchrotron radiation at SPring-8 is realized. Specially designed apparatus including X-ray optics achieves both high energy-resolution and high efficiency comparable with the soft X-ray photoemission spectroscopy. Large probing depth of about 10 nm enables us to probe intrinsic bulk electronic structure free from surface condition and electronic structure of deeply-buried layers. The importance and capability of this technique are demonstrated by the drastic difference in the Mn 2p core-level photoemission spectra of La_1-xSr_xMnO₃ thin films that is obtained by using soft and hard X-rays.