PURPOSE: To obtain the piezoelectric resonance element which varies a little in resonance frequency and resonance impedance owing to a thermal shock by heating piezoelectric ceramic up to specific temperature after baking, and then annealing it at a necessary temperature drop speed.

CONSTITUTION: A piezoelectric composition is used and the piezoelectric ceramic is baked and heated up to higher Curie temperature and lower than grain growth start temperature. Then the temperature area including the Curie temperature is annealed at the drop speed of -50°C/Hr--10°C/Hr. Then a polarization electrode 2 is formed. This method relaxes thermodynamic unstableness generated in the crystal phase of the piezoelectric ceramic and the internal strain is also reduced. Even when a thermal shock is applied to the piezoelectric ceramic after polarization, variation in piezoelectric characteristics are suppressed small and the piezoelectric element which varies a little in resonance frequency and resonance impedance owing to the thermal shock is obtained.