Electric force microscopy (EFM) testing is a new contact-less, circuit internal test technique for function and failure analysis of integrated circuits (ICs), which combines both high temporal and high spatial resolution. Thus, EFM testing is a promising tool for the test of future IC generations. However, there are still not completely investigated problems as the cross-talk problem, which especially has to be considered for IC-testing of sub-micrometer conducting lines. Therefore, in this paper measurements by EFM testing on parallel sub-micrometer conducting lines are presented, which clarify the cross-talk caused falsification of measurement results. A calculation model is introduced, which takes the cross-talk into consideration and allows a better interpretation of EFM testing results.