A piezoelectric transformer driver circuit can employ low voltage transistors. By alternately turning ON and OFF switching transistors b 3 and 4 depending upon gate signals GA and GB, a primary side of a piezoelectric transformer 7 is driven, and a secondary side is connected to a load 8. Inductors 1 and 2 are provided corresponding to transistors 3 and 4 for supplying a power source to corresponding transistors. Capacitors 10 and 11 respectively connected to one of the electrode of the inductors 1 and 2, respectively. The transistor 12 is turned ON upon completion of ON/OFF operation of the transistors 3 and 4, and the capacitors 10 and 11 are situated the other electrode at the ground voltage. Upon completion of ON/OFF operation of the transistor, a surge voltage to be generated by the inductors 1 and 2 can be restricted to permit use of the low voltage transistor. Thus, the overall circuit can be compact and low cost.