Abstract: A LTQ (light triggered & quenched) static induction thyristor circuit of the present invention is to provide a LTQ static induction thyristor circuit obtaining an excellent dv/dt capability and operating ambient temperature characteristics, a large optically controllable current capability, and simple structure. A main static induction thyristor turns on when its gate receives an optically triggering pulse and causes a current to flow through a load from a positive terminal of a power supply. A photothyristor turns on when its gate receives an optically quenching pulse and causes the gate to a negative power supply voltage to turn off. At this point, a first resistor functions in such a manner as to hold turned on for a predetermined time period even after application of has been ended. By the flow of such current through a first resistor, the gate is biased to a negative voltage.