The dispersed fluorescence of the Ã 2A1-X̃ 2E system of CH3O and 13CH3O in a supersonic jet was recorded after excitation of various vibrational levels of the A state. Analysis of the spectra yielded v″2 = 1412, v″3 = 1047, v″5 = 1494, and v″6 = 653 cm-1 for the X̃ state of 12CH3O, and v″2 = 1408, v″3 = 1027, v″5 = 1488, and v″6 = 649 cm-1 for 13CH3O. The least-squares fitting of the observed 300-3 60 lines (with spin-orbit splitting removed) yielded ωe=1057±3 cm-1 and ωex e =7.0±0.7 cm-1 for v″3 of 12CH3O. Several tentative assignments were also made on the basis of the improved fluorescence spectra. The Fermi-resonant levels 1289 and 1319 cm-1 above v=0 of the Ã state were also reassigned; the former is better represented as v′2 = 1, whereas the latter is represented as v′3 = 2.