A spin cast film of poly(2,6 dimethyl-1,4-phenylene oxide) [PPO, also known as PPE, poly(phenylene ether)] was analyzed by XPS using monochromatic AlKαexcitation. The measured atomic composition closely matched the expected stoichiometry of the polymer. Peak positions of the individual chemically shifted C 1sand O 1scomponents are reported. The results are in general agreement with other reported spectra of polyphenylene polymers: experimental, C 98.2% and O 10.8%; theoretical, C 88.90% and O 11.1%.