The millimeter- and submillimeter-wave spectrum of AuF in the X(1)Sigma(+) state was observed by employing a source-modulated microwave spectrometer. The AuF molecule was generated in a free space cell by the sputtering reaction from a gold sheet lining the inner surface of a stainless steel cathode using a dc glow plasma of CF4 and Ar. Rotational transitions in the highly excited vibrational states enabled to determine Dunham-type molecular constants by a least-squares fit. Other constants like dissociation energy D-e, vibrational wavenumber omega(e), and its anharmonic term omega(e)x(e) were also derived from the obtained constants. (C) 2002 Elsevier Science B.V. All rights reserved.