The unimolecular metastable decompositions of bis(2,2,2-trifluoroethyl) ether, CF3CH2OCH2CF3 (1), and ethyl 2,2,2-trifluoroethyl ether, CH3CH2OCH2CF3 (2), induced by electron ionization, have been investigated by mass-analyzed ion kinetic energy (MIKE) spectrometry and energy-dependent collision-induced dissociation (CID) spectra in conjunction with thermochemical data. In the metastable time window, the molecular ions of 1 decompose into the ions at m/z 113 by the loss of CF ῌῌ and 2 ῌῌ decompose in a variety of ways: in addition to the fragment ion m/z 65, which is generated by the elimination of CHFO, four other fragment ions with m/z 83, 63, 61, and 31 are observed , which correspond to the competitive losses of CH2O, (CH2OῌHF), CH2F2, and C2HF3 (or C2H4F2O), respectively.