I09 is designed for high-resolution studies of atomic and electronic structures of surfaces and interfaces using Photoelectron Spectroscopy (PES), Near Edge X-ray Absorption Fine Structure (NEXAFS), X-ray Standing Waves (XSW), Photoelectron Diffraction (PhD) and X-ray Reflectivity (XRR). To apply the different techniques to the same sample, and to access more absorption edges, which can be highly beneficial in solving complex surface problems, two canted undulators installed in a modified long straight section are used to provide both soft (100 - 2100 eV) and (2.1 - 20 keV) hard x-rays, which are directed to illuminate the same spot on the sample in one of the end-stations that is equipped with a high-energy electron analyzer. Such a wide photon energy range, which can be translated into an electron mean free path of 0.5 to larger than 5 nm, also offers a unique opportunity for probing the electronic structures of buried layers and interfaces in either an angle-integrated or angle-resolved mode. The beamline design includes also a soft x-ray side branch to be realised in a later stage, with additional end-stations for PES, NEXAFS and angle-resolved PES being considered.