The appearance of the chemiluminescence spectra from the reactions of the alkaline earth metals M = Ca and Sr with SF6 is only understood by the participation of excited metal atoms in the reactions. This has been ascertained by measuring the dependence of the intensities of the metastable Ca-line 657.3 nm and of a representative CaF band on the SFg gas pressure in the reaction chamber. By a detailed analysis of the well resolved A -X-and B -X-systems of both of the reactions some earlier values of Do(F-SF5) given in the literature can be excluded, while the recently found value (Kiang et al.) of 3.9 ±0.14 eV is well confirmed.