PURPOSE: To attain high sintered density, to inhibit abnormal grain growth, to prevent peeling and warpage at the time of firing in a laminated state and to increase electromechanical coupling factor, relative dielectric constant and piezoelectric constant by imparting a specified compsn.

CONSTITUTION: Powders of PbO, TiO2, ZrO2, MgO, Nb2O5, SrCO3, BaCO3 and CaCO3 each having 0.1-2μm particle diameter are mixed, pulverized, calcined and crushed to obtain calcined powder having 0.3-1μm particle diameter and 0.5-2m2/g specific surface area. An org. binder is added to the calcined powder and they are compacted and fired at 1,150-1,200°C in the air for 1-2hr to obtain the objective piezo-t, electric porcelin compsn. represented by the formula aPb(Mg1/3Nb2/3)O3.-bPbTiO3.cPbZrO3.dNb2O5 (where 0.05≤-a≤0.25, 0.30≤b≤0.55, 0.025≤-c≤0.30, a+b+c=1 and 0,0005≤d≤0.25).