Piezoelectric actuator and liquid ejecting head

A piezoelectric actuator comprising:

• a first insulation layer provided on a surface of a substrate;
• a conductive layer provided on the first insulation layer;
• a second insulation layer provided on the conductive layer;
• a piezoelectric element provided on a part of the second insulation layer, the piezoelectric element including a first electrode, a piezoelectric body, and a second electrode in this order;
• a third insulation layer covering at least a part of the second insulation layer, the first electrode, the piezoelectric body and the second electrode;
• a first contact plug penetrating the second insulation layer and the third insulation layer, and having one end electrically connected to the conductive layer;
• a second contact plug penetrating the third insulation layer, and having one end electrically connected to either one of the first electrode or the second electrode;
• and
• a wiring line provided on the third insulation layer, and electrically connecting another end of the first contact plug and another end of the second contact plug.