A control circuit of a light-emitting element comprises a rectifying unit (30), a switching element (38), a transformer (48) having a first winding (L1) which generates a magnetic field using a current controlled by switching of the switching element (38), a second winding (L2) which is magnetically coupled to the first winding (L1) and which generates a current flowing to an LED (102), and a third winding (L3) which is magnetically coupled to the first winding (L1) and which generates a voltage (Sfbk), and an averaging capacitor (32) which averages a voltage derived by superposing a voltage (Srec) rectified by the rectifying unit (30) and the voltage (Sfbk), and a voltage averaged by the averaging capacitor (32) is applied to the first winding (L1), so that light is emitted from the LED (102).