An apparatus for selectively destroying dividing cells in tissue, the dividing cells having polarizable or polar intracellular members, the apparatus comprising: a first insulated electrode (230; 1210) having a first conductor and a first dielectric member that is in contact with the first conductor, the first dielectric member being for placement against the tissue to form a capacitor; a second insulated electrode (230; 1200) having a second conductor and a second dielectric member that is in contact with the second conductor, the second dielectric member being for placement against the tissue to form a capacitor; an electric field source connected to the first and second insulated electrodes (230; 1210, 1200) for applying an alternating electric potential across the first and second conductors, wherein passage of the electric field through the dividing cells in late anaphase or telophase transforms the electric field into a non-homogenous electric field that produces an increased density electric field in a region of a cleavage furrow of the dividing cells, wherein the electric field source comprises a generator that generates an alternating voltage waveform at frequencies between 50 kHz to 500 kHz, whereby the non-homogeneous electric field produced within the dividing cells is of sufficient intensity to move the polarizable intracellular members towards the cleavage furrow; characterised by: the voltage waveform generated by the generator being adapted to provide an electric field intensity in the tissue to be treated of between 0.1 V/cm to 10.0 V/cm; a temperature sensor for sensing temperature of the tissue; and a controller which controls the amplitude of the electric field generated by the electric field source so as not to generate excessive heating of the tissue. a first insulated electrode (230; 1210) having a first conductor and a first dielectric member that is in contact with the first conductor, the first dielectric member being for placement against the tissue to form a capacitor; a second insulated electrode (230; 1200) having a second conductor and a second dielectric member that is in contact with the second conductor, the second dielectric member being for placement against the tissue to form a capacitor; an electric field source connected to the first and second insulated electrodes (230; 1210, 1200) for applying an alternating electric potential across the first and second conductors, wherein passage of the electric field through the dividing cells in late anaphase or telophase transforms the electric field into a non-homogenous electric field that produces an increased density electric field in a region of a cleavage furrow of the dividing cells, wherein the electric field source comprises a generator that generates an alternating voltage waveform at frequencies between 50 kHz to 500 kHz, whereby the non-homogeneous electric field produced within the dividing cells is of sufficient intensity to move the polarizable intracellular members towards the cleavage furrow; characterised by: the voltage waveform generated by the generator being adapted to provide an electric field intensity in the tissue to be treated of between 0.1 V/cm to 10.0 V/cm; a temperature sensor for sensing temperature of the tissue; and a controller which controls the amplitude of the electric field generated by the electric field source so as not to generate excessive heating of the tissue. the voltage waveform generated by the generator being adapted to provide an electric field intensity in the tissue to be treated of between 0.1 V/cm to 10.0 V/cm; a temperature sensor for sensing temperature of the tissue; and a controller which controls the amplitude of the electric field generated by the electric field source so as not to generate excessive heating of the tissue.