A liquid jet head includes a base plurality of pressure chambers which include recesses, respectively, arranged in a front surface of a base. A piezoelectric substrate is joined to upper surfaces of side walls of the recesses and is uniformly polarized in a direction parallel to a substrate surface of the piezoelectric substrate. A pair of a front surface drive electrode and a back surface drive electrode are provided on a front surface of the piezoelectric substrate, which is opposite to the pressure chamber side, and on a back surface of the piezoelectric substrate on the pressure chamber side, respectively, for each chamber and sandwich the piezoelectric substrate therebetween and extend to a side wall of the recess substantially from a center of the open end. A liquid chamber is formed in the base and communicates with the pressure chambers via openings formed in bottom surfaces or side wall surfaces of the recesses, respectively.