Multi-layer piezoelectric element, and injection device and fuel injection system using the same

A multi-layer piezoelectric element, comprising:

• a columnar stacked body comprising
• an active portion comprising a plurality of piezoelectric layers and a plurality of internal electrode layers alternately laminated, and
• inactive portions comprising a plurality of piezoelectric layers laminated, the inactive portions arranged at both ends in a stacked direction of the active portion;
• and
• a pair of external electrodes arranged on side faces of the columnar stacked body, the pair of external electrodes electrically connected to the internal electrode layers alternately, wherein
• in at least one interlayer portion of the piezoelectric layers of the inactive portions, there are metal particles having a particle size smaller than that of piezoelectric ceramic particles forming the piezoelectric layers of the inactive portions, and
• the metal particles are scattered in a range including a region in which the internal electrode layers overlap each other when viewed in the stacked direction of the columnar stacked body.