[en] We present theoretical calculations of double differential cross sections (DDCS) for methane molecule. Angular distributions of secondary electrons have been measured after ionizing electron collisions with methane at primary energy of 350 eV using a conventional electron spectrometer. The theoretical model used is the first and second Born approximations with Gamow factor. It is found that these theoretical calculations are successful to describe the post-collision interaction effects due to the Coulomb long-range interaction between the outgoing electrons in the final state. (paper)