The adsorption of furan on Si(111)-7x7 has been investigated at room temperature and at 90K using X-ray photoelectron spectroscopy (XPS). The presence of two C1s photoelectron peaks at room temperature is consistent with the existence of two molecular adsorption states and with a proposed adsorption model of thiophene and furan on Si(111)-7x7, which involves a surface-parallel π-bonded geometry and a σ-bonded geometry through the oxygen atoms. The C1s photoelectron spectra have also been collected after annealing the sample to 350K. The effect is the preferential molecular desorption of the surface-parallel π-bonded geometry.