the piezo stack 2 consists of a plurality of vertically stacked layers of piezo elements 3 an electrode layer being disposed between the individual piezo elements 3 for electrical contacting of the piezo stack 2 a metallization 4 which extends over the entire length of the piezo stack 2 is applied to two opposite lateral surfaces of the piezo stack the individual electrode layers of the piezo stack 2 being connected alternately to the metallization 4 and the opposite metallization not shown in the drawing for assembly of a piezo actuator the preassembled piezo stack 2 is inserted in the assembly mount 1 for this purpose the assembly mount 1 is cage shaped and has two end plates 5 6 which are interconnected by longitudinally running ribs 7 8 a cutout 9 10 being disposed in each of the two end plates 5 6 through which cutout 9 10 the piezo stack can be inserted in the assembly mount 1 in the assembled state the piezo stack 2 then protrudes slightly from the assembly mount 1 in the axial direction through the cutouts 9 10 said cutouts 9 10 thereby fixing the piezo stack 2 in the upper end plate 5 bores to accommodate the connection pins 11 12 are additionally provided laterally adjacent to the cutout 9 while the lower end plate 6 has a clamp bearing 13 which is molded to the end plate 6 in a monolithic manner and guides the lower end of the connection pins 11 and 12 in the transverse direction the lower end of the connection pins 11 and 12 resting on the upper side.