A piezoelectric actuator capable of being driven with a high electric field intensity, obtaining a larger displacement and being high in electric conducting reliability of electrodes, and comprising: at least one cell defined by two side walls, a substrate and a ceiling wall; the two side walls being disposed on the substrate and being covered with the ceiling wall to define one cell, at least the two side walls comprising piezoelectric/electrostrictive devices, and the piezoelectric/electrostrictive devices being capable of changing a volume of the cell by displacement of the walls. Each of the piezoelectric/electrostrictive devices comprises a plurality of layered piezoelectric/electrostrictive bodies and electrodes which are alternately stacked, and end portions of the electrodes are embedded in the piezoelectric/electrostrictive bodies in at least the internal side of the cell.