Researchers at Institute for Molecular Science (IMS), Innovation Research Center for Fuel Cells, University of Electro-Communications, Research Center for Materials Science, Nagoya University, and JASRI (Japan Synchrotron Radiation Research Institute), have improved an ambient-pressure photoelectron spectroscopy instrument using hard X-rays produced at SPring-8 and succeeded in photoelectron spectrometry under real atmospheric pressure for the first time in the world. Their achievements has been published online in the Applied Physics Express.