In the study of the interaction of dimethyl ether with alumina-supported platinum metals by means of infrared spectroscopy, methoxy species bonded to the alumina and CO adsorbed on the metals have been detected. The complete oxidation of dimethyl ether in a flow system sets in above 400 K and proceeded to 100% conversion at similar to 673 K. No or only very slight deactivation was observed in 5 h. The specific activity order of the catalysts is : Ru > Pt > Ir > Pd > Rh.