The gas-phase electron resonance spectrum of the CF radical in itsX2π3/2electronic state is described. Analysis of the spectrum gives values of the rotational constantB0and fine structure constantAwhich are in good agreement with those previously obtained from the ultra-violet emission spectrum. The axial component of the19F magnetic hyperfine interaction is derived, and significant contributions from the non-axial components are discussed. The electric dipole moment of CF is obtained from measurements of the first-order Stark effect.