PURPOSE: To obtain a circuit in which the small fluctuation of a reference voltage is sufficient even when a dispersion exists at a drain current characteristic at a transistor to divide a supply voltage by providing a first transistor group and a second transistor group inserted between a positive side power source line and a negative side power source.

CONSTITUTION: A voltage partially divided by one Tr such as a transistor (Tr)Q11 to belong to a group A is 0.22V, the voltage due to a Tr Q21 to belong to a group B is 0.23V and at the time of termination voltage Vrr= 2.0V, a reference voltage VREF of the inverse of 1.3V is obtained from a connecting point N. In this constitution, respective TrQ11... and Q21 are ordinary threshold voltages, namely, the voltage having the inverse of 0.5 the inverse of 1.0V, the I-V characteristic becomes the one which crosses at a triode area. Since a drain voltage impressed to TrQ11... Q21... is almost equal, the fluctuation of a voltage VREF can be minimized even when a threshold voltage is dislocated from a design value.