We have simulated electron acceleration under short intense impulse electric fields of 0.1–1 kV cm-1 strength and ~1 ns duration in N2 at 65.5 Pa. The electron acceleration is completed in a practically collisionless condition when the impulse duration is comparable with or shorter than the electron mean free time. On the basis of this feature, we have proposed a way to produce a group of monoenergetic electrons. The electron energy after acceleration is controllable by the impulse strength and duration, and we have demonstrated selective promotion of the excitation producing N2(A 3?u+) metastable excited molecules. The selectivity has been quantified as the efficiency of the electron energy utilized for the target reaction, and efficiencies of 20–30% have been achieved in this simulation. These values are higher than those of electron swarms in DC equilibrium, in which the efficiency is at most 10%. The electron behaviour under impulse electric fields and the dependence of the energy efficiency on the impulse profile have been investigated.