Chemical state analysis by a combination of X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) using synchrotron radiation is performed for β-FeSi2 single crystals and homoepitaxial β-FeSi2 films. The Si 2p XPS and Fe L-edge XAS spectra imply that the annealing at 1173K to remove native oxide layers on the crystal induces the formation of FeSi in the surface. The formation of FeSi is also confirmed by Si K-edge XAS analysis. For the homoepitaxial β-FeSi2 films grown on the crystals, the Si K-edge XAS spectra indicate that structurally homogeneous β-FeSi2 films can be grown on the β-FeSi2 single crystals when the substrate temperatures of 973 and 1073K are applied for molecular beam epitaxy (MBE). Consequently, it is indicated that the combination of XPS and XAS using synchrotron radiation is a useful tool to clarify chemical states of β-FeSi2 single crystals and homoepitaxial β-FeSi2 films, which is important to reveal optimized growth conditions of homoepitaxial films.