Abstract: An uninterruptive switching regulator includes, at a primary side, a rectifier circuit, a primary winding of a high-frequency transformer, a primary side switching element, and a switching primary winding, and at a secondary side, a secondary side output circuit having a rectifying and smoothing circuit connected, and at a tertiary side, a tertiary winding, a charge and discharge circuit, a tertiary side switching element, an electrical double layer capacitor, and a switching tertiary winding, respectively. An output is transmitted from the primary side and tertiary side to the secondary side by the flyback system, and when the output voltage of the rectifier circuit at the primary side exceeds a predetermined level, the charge circuit operates, whereas when it does not exceed the predetermined level, the discharge circuit operates.