A method and device for switching power semi-conductors on and off, especially for IGBTs and MOS-FETs with inductive loads, and how they would be employed with torque-variable asynchronous machines, in ignition systems for spark ignition engines, in switch mode power supplies and power factor controllers. During a switching operation of the power semiconductor, a voltage across the semiconductor and the current through the semiconductor are measured, a time function of the voltage as well as a time function of the current are controlled, and the control of the voltage time function and the control of the current time function are effected essentially one after the other.