To solve the problem in the conventional DC current detectors that measurement errors become large in the by eliminating failures in the holding of the ground level of an integrator at 0 V attributed to a larger capacity of a capacitor required so far for mainly determining the gain of the low frequency band that disables quick discharging of electric charges.
The DC current detector is provided with reset switches C1 and C2, which are connected in parallel respectively to capacitors C1 and C2 that affect the ground level of the integrator 3 as components of the integrator 3, to discharge electric charges accumulated in the capacitors C1 and C2 and control means 6 and 7, which perform a control to operate the reset switches 4 and 5 during the currentless period of the current to be measured.
MIZOHATA FUMIO