PURPOSE: To obtain a constant current characteristic over a wide range even at a low power voltage by forming a current mirror circuit with the 1st FET on the reference side and the 1st FET on the output side and applying current mirror connection to the 2nd FET on the reference side and the 2nd FET on an output side.

CONSTITUTION: When a reference current Iref1 flows, a gate-source voltage VGS1 of an N-channel FETQ1 (reference side 1st FET) whose gate and drain are connected is fed to a gate of a FETQ2 (output side 1st FET), and when a reference current Iref2 flows, a gate-source voltage VGS4 of an N-channel FETQ4 (reference side 2nd FET) whose gate and drain are connected is fed to a gate of a FETQ3 (output side 2nd FET), the FETs Q2, Q3 are connected in series and its drain current is used as an output current Iout. Thus, even when a power voltage lower to be a threshold voltage (0.5-1.0V) of MOSFETs is employed, the operation with high accuracy is realized.