PURPOSE: To compensate accurately the fluctuation of a general electronic circuit characteristic widely and automatically by changing the amplification factor of an input voltage in response to a resistance of a variable resistive element changing corresponding to temperature change so as to use the increase in a voltage level thereby compensating the fluctuation of the electronic circuit characteristic due to temperature decrease.

CONSTITUTION: When temperature decreases, e.g., below 0°C, a resistance of a posistor 1b decreases, a potential at a point B of a temperature signal generating circuit 10 decreases, the conduction of a diode 5 is stopped and the parallel connection with a resistor 1d is released. Thus, the resistance change in the posistor 1b is inputted to a terminal 2b of a differential amplifier 2 directly, the difference is increased depending on the temperature decrease to control the collector current of a transistor 3 based on the signal level outputted from an output terminal 2c of the differential amplifier 2 according to the difference and the voltage outputted at a voltage output terminal C is controlled. An input voltage from a terminal A is amplified based on the resistance change is the posistor 1b, outputted from the terminal C and inputted to the electronic circuit such as an oscillator and an amplifier thereby compensating the frequency fluctuation of the oscillator.