Abstract: A gate turn-off thyristor comprising, a first emitter layer of one conductivity type, a main base layer of another conductivity type connected to said first emitter layer and a control base layer of the first conductivity type connected to the main base layer. A second emitter of the other conductivity type is connected to the control base layer at a junction which surrounds a portion of the second emitter layer. An emitter contact is connected to the second emitter layer and a control base contact is connected to the control base layer. The gate turn-off thyristor is turned off by a short circuiting of the control base contact with the emitter contact. The surface resistance of the control base layer between the second emitter layer and the control base contact is selected so that, with a control base turn-off current applied which is sufficient for turning off the thyristor, a potential appears on a lateral resistance in the control base layer which is less than a potential appearing at the junction.