PURPOSE: To provide a charge current detecting circuit for quickly and accurately detecting the end of charge of an electrostatic capacitance.

CONSTITUTION: A current is detected in different timings with a couple of sample and hold circuits 20, 21 and the signal held by the sample and hold circuits 20, 21 is subtracted in a subtractor 22 to obtain a difference of current. The difference obtained is compared with the reference voltages V1, V2, V3, with comparatos 23, 24, 25. A current difference is decided depending on the result of comparison to control the timing of sample of the sample and hold circuits 20, 21. When a difference is fixed to almost zero, a charge end signal is outputted.