In the current detection circuit that detects the output currents of a switching power supply circuit, an improved current detection circuit makes it possible to detect the output current directions of power supplies solves the malfunction of the power supplies vibrating or diverging during changes in load state and during parallel operation, and thus implements stable operation. The direction of an output current I2 can be detected by using the current detection circuit 8 that has multiple switching elements S1 to S4 each operating synchronously with an inverter circuit.