Abstract The use of the 90° hemispheric electrostatic high resolution analyzer in conjunction with the time-of-flight (TOF) technique allowed us to identify various species associated with the ionization of methane molecular gas by a pulsed fast 19 MeV F4+ beam. We were able to measure the yields of single and double ionization-dissociation species of H+, H 2 + , C+, C2+, CH+, C H 2 + , C H 3 + , C H 4 + and C H 4 2 + . We reported the single- and total ionization cross sections of C H 4 + and the daughter ions- C H 3 + , C H 2 + , CH+ and C+. Our results show that the single ionization cross sections of C H 4 + and C H 3 + are in good accord with those found in literature, however, the cross sections of C H 2 + , CH+ and C+ are in disagreement with the ones found in literature.