PURPOSE: To obtain a controller for the local oscillating frequency miniaturized and simplified at a lower cost more than a conventional AFC circuit.

CONSTITUTION: When temperature information detected by a temperature sensor 1 and obtained through an A/D converter 2 and time information 3a detected by a timer 3 are inputted to a control processing section 5, the control processing section 5 extracts control voltage information 4a corresponding to the temperature information 2a and the time information 3a from a memory 4 and outputs it to a D/A converter 6. The D/A converter 6 outputs its D/A- converted control voltage signal 6a to a resistor R2 and the control voltage signal 6a is added to an offset voltage via a resistor R1 and the sum is outputted through an operational amplifier 10. The added control voltage signal 10a is outputted to a local oscillator 11, which outputs a stable local oscillation frequency 11a to a mixer 13 by using the control voltage signal 10a.