A memory device is provided comprising a transistor having a floating body positioned between source and drain regions, the floating body being sandwiched between first and second insulated gates each comprising a gate electrode. A control circuit is arranged to program the state of said floating body to have an accumulation or depletion of majority carriers by applying one of first and second voltage levels between the first gate and at least one of the source and drain regions, and to retain the programmed state of said floating body by applying a third voltage level to the second gate. The voltages are switched over a time duration shorter than 100 ns.