Using Monte Carlo methods, this study investigates energy deposition of energetic electrons and ionization in the 2019 novel coronavirus by electron irradiation, which are important characteristic quantities related with biological damage formation. The inelastic scattering of low-energy electrons (<10 keV) was calculated by dielectric theory. The optical energy-loss functions of viral proteins and RNA were derived from an empirical method in the energy-loss range <40 eV and the calculation of optical parameters of the biomolecules. The densities and distributions of energy deposition and ionization were calculated from the stopping power and inelastic cross-sections in the electron-cascade simulation. Electrons with primary energies of approximately 1–3 keV produced significant energy deposition and ionization in the target coronavirus. More energetic electrons were less effective due to the larger electron range and fewer scattering events in the coronavirus.