Monte-Carlo simulation is used to study the surface recombination effects on the electron beam induced current technique. The current is collected by a nanoscale electrode. We choose three values for the surface recombination velocity reflecting the sample surface states; zero, infinite value and an intermediate one. From a probabilistic point of view, each of the three surface velocities is described by a collection probability related to the surface effects and to the electrode size. Even if probabilities corresponding to zero and intermediate velocity are chosen to be close one to the other, the results are different. For intermediate velocity the collection efficiency profile is similar to that corresponding to the infinite velocity. Both profiles narrow with diminution of their maximum. At electron beam energies higher than 4 keV the profiles are superimposed because of the large penetration depth, and the smallness of the electrode and its depletion zone.