PURPOSE: To obtain a load current detecting circuit having a simple structure at low cost in which no spike noise is generated at the time of switching each switch and the range for switching the current detection sensitivity can be widened without increasing the number of DAC.

CONSTITUTION: First and second current detection resistors 20, 22 are connected in series between an operational amplifier 18 and a load 24. A switch 26 is connected across one resistor and the load voltage is detected through a voltage detector 32. Output voltage from a DAC 36 is then controlled to feed a load with a voltage identical to a detected voltage. Subsequently, a switch 40 is turned ON and an FET is gradually turned ON. Thereafter, the output voltage from the DAC 36 is decreased and the voltages across the first and second resistors 20, 22 are brought to zero. Finally, the switch 26 is turned ON to switch the current detection resistor.