PURPOSE: To block the deterioration in characteristics such as data error rate and to improve the performance of an optical receiver, by compensating the dark current temperature characteristics of a photoelectric conversion element for photodetection through the use of the temperature characteristics for the forward current, dark current or transmission current of a diode separately provided.

CONSTITUTION: A voltage e1 of a connecting point between a photodetection PIN diode 1 and a load resistor RL is applied to an inverting input terminal of a head amplifier 2 and a voltage e2 between a silicon diode 4 with a back bias and a resistor R1 in series is applied to a non-inverting input terminal. The temperature characteristics of reverse current of the diode 4 is made equal to the temperature change of the dark current of a photodiode 1, an output DC voltage e0 of the amplifier 2 is set to zero and the output of a comparator 3 compared with a reference voltage e3 can always be kept constant. In compensating the output of a constant voltage source 5, the silicon diode 4 is connected in series with the resistor R1 of the output side of the voltage source 5, and the reference voltage e3 and the output of the amplifier 2 can always be made equal with the temperature characteristics of the diode 4.