PURPOSE: To facilitate the easy designing of the FM receiver by using the variable capacity diode possessing the several electrode structures of both the depletion layer control part containing the control electrode which gives the control to the width of the depletion layer and the capacity reading part containing the reading electrode which fetches the capacity variation each.

CONSTITUTION: The parametric mixer is formed with use of the variable capacity diode possessing several electrode structures of depletion control parts 13 and 14 plus capacity reading part 12. With appeication of input signal VS (reception frequency f1) and local oscillation signal voltage VP (local oscillation frequency f2) to the depletion layer part and the capacity reading part respectively, the mixing of f2=f1+ f3 or f2=f1-f3 is carried out in relation to output signal voltage VO (intermediate frequency f3). This is due to the following fact: the width of the depletion layer caused under part 12 is varied by giving the adverse bias to parts 13 and 14 via the control electrode each, and accordingly the capacity change can be fetched via the capacity reading electrode.