The dissociation of energy-selected methyl fluoride ion CH3F+ along the CH3+ and F formation channel has been investigated in detail in the 12.2-19.8 eV energy range. Three low-lying electronic states of the CH3F+ ion, (XE)-E-2, A(2)A(1), and (BE)-E-2, were prepared and analyzed by the method of double imaging photoelectron photoion coincidence (i(2)PEPICO). Three types of CH3+ fragment ions corresponding to the dissociation of (XE)-E-2, A(2)A(1), and (BE)-E-2 electronic states have been observed and identified through their kinetic energy release distribution (KERD) curves, showing that the dissociation of the CH3F+ ion in the different electronic states along the CH3+ formation channel is state-specific, even outside of the FranckCondon region. Highly excited vibrational levels of the (XE)-E-2 ground state can be populated through a resonant or near-resonant autoionization process and undergo vibrational predissociation into CH3+ fragment ions. The A(2)A(1) first excited state is repulsive along the F-loss coordinate, and its dissociation is direct and fast. The CH3F+ ions in the (BE)-E-2 excited state first undergo an internal conversion toward the hot cation ground state (XE)-E-2 and then statistically dissociate into CH3+ and F fragments.