In the method for detecting a current, the current is detected by a first current sensor in a predetermined sampling period as a digital value, and is detected by a second current sensor in a period longer than the first current sensor with high accuracy as a digital value. In the method for detecting a current, the current during detecting-incapable time period, which is incapable of detecting the current during detecting timing for detecting the current during the predetermined period by the second current sensor, is complemented with the current value detected by the first current sensor,