The permeability of a cell membrane can be transiently increased locally when an external electric field pulse with an overcritical intensity is applied. A position dependent modulation of the membrane potential difference is induced during the pulse. A local membrane alteration is created, which may reseal. Its molecular definition remains unknown. This phenomenon is now commonly known as electroporation or electropermeabilization. The former term implies that physical pores are created in the lipid matrix. However their existence has never been clearly demonstrated. The term electroporation is therefore rather misleading.