Angle-resolved photoemission spectroscopy (ARPES) has been performed on quasi-one-dimensional Li0.9 Mo6 O17 using photon energy hν=500 eV. Measured band dispersions are in agreement with those from both low-photon-energy measurements and band structure calculations. The momentum-integrated ARPES spectrum is well fitted by the finite-temperature Luttinger liquid (LL) spectral function, with an anomalous exponent 0.6 that is the same within experimental uncertainty as the value found with hν=30 eV. These identical findings at both low and high hν are entirely consistent with reasoning based on the crystal structure that the quasi-one-dimensional chains lie two layers below the cleavage plane so that the observed spectroscopic LL behavior of Li0.9 Mo6 O17 is a bulk property. © 2006 The American Physical Society.