High resolution photoemission spectroscopy with soft X-ray synchrotron radiation has been applied to montmorillonite, one of phyllosilicate compounds. Charge build-up is inevitable in the powder sample due to its insulating property so that photoemission peaks of element components are difficult to be assigned. On the other hand, photoemission peaks have been observed at their original peak positions without the charge shift. These non-shifted peaks enabled determination of binding energies of element components. Information on chemical bonding states of cesium, adsorbed artificially in the montmorillonite, has been also obtained.