The secondary emission coefficient, delta, of a given solid changes upon bombardment of the surface by an electron beam of high current density. Secondary emission and work function changes were measured simultaneously by work function spectroscopy during electron irradiation. The decrease of secondary emission and a successive increase of work function occurred on contaminated Si and W plates. The dependence of the work function- and the secondary emission change on primary energy was observed to be qualitatively the same. The change of delta as a function of primary electron energy has a maximum in the energy region where the mean free path of primaries and secondaries lies in the same range. From the results it can be assumed that the wlow energy secondaries have a great influence on Deltadelta. (C) 2003 Elsevier B.V. All rights reserved.