Results of experimental investigation of copper cathode erosion in magnetically driven arc versus arc current, arc velocity and electrode surface temperature are presented. The experiments showed the presence of two different erosion regimes as function of current and temperature. First, erosion slowly grows for low values of these parameters, then, a sudden increase of erosion occurs. A critical temperature of about 500−600 K for this transition was found for magnetic fields in the range 0.01−0.35 T. We observed that, besides the decrease of erosion for low arc velocities, erosion can also increase for high velocities, contrary to what was expected. A reasonable agreement to predictions of a previously published erosion model is obtained.