To provide a stacked piezoelectric device which is inexpensive and excellent in bonding strength between a piezoelectric layer and an internal electrode layer, the piezoelectric device comprises piezoelectric layers and internal electrode layers containing not less than 50 percent by weight of Cu stacked alternately. Between the internal electrode layer and the piezoelectric layer, there is a diffusion region formed by mutual diffusion of components of the internal electrode layer and the piezoelectric layer to the other layer and comprising at least one component of the piezoelectric material and Cu. The diffusion region occupies not less than 90 percent of area of interface between the internal electrode layer and the piezoelectric layer, and a thickness of the diffusion region is not more than 10 percent of a thickness of the internal electrode layer. A piezoelectric material constituting the piezoelectric layer preferably comprises PZT which is a Pb(Zr,Ti)O3— based oxide having a perovskite structure, and Pb, Cu, and O elements coexist in the diffusion region.