an object of the present invention is to lower the voltage applied to the starting resistor of the starting circuit in a switching power supply circuit to reduce the power loss especially when the receiving voltage is high and thereby provide a small and inexpensive switching power supply circuit . according to the present invention , a switching power supply circuit comprises : a dc voltage section having two or more capacitors connected in series ; and a pwm control circuit for receiving dc power supply from the dc voltage section and performing switching control on a primary side of a transformer in order for the switching power supply circuit to output a dc voltage of different voltage specifications ; wherein the starting resistor for the pwm control circuit is connected to a connection point of the capacitors .