Multi-layer piezoelectric element and injection apparatus using the same

A multi-layer piezoelectric element and an injection apparatus using the same are provided. The piezoelectric element comprises a stack (10) having a plurality of piezoelectric layers (1) and a plurality of inner electrodes (12), the piezoelectric layers and the inner electrodes being stacked alternately one on another, and a pair of external electrodes (15) formed on side faces of the stack, wherein an isolated section (16), of which thickness gradually decreases toward the periphery and which is separated from the side face of the stack, is formed in a peripheral portion (15a) of the external electrode.