Piezoelectric device and piezoelectric filter

A piezoelectric device comprising:

• a piezoelectric layer including a thickness in a first direction, and an upper surface defining one of surfaces in the first direction and a lower surface defining another one of the surfaces in the first direction;
• a support on a side of the lower surface of the piezoelectric layer;
• an upper electrode on the upper surface of the piezoelectric layer;
• a lower electrode on the lower surface of the piezoelectric layer with at least a portion of the lower electrode facing the upper electrode;
• and
• a reinforcement film on at least one of the upper surface and the lower surface of the piezoelectric layer;
• wherein
• the support includes a space portion in a region overlapping with at least a portion of the upper electrode and the lower electrode;
• and
• in plan view seen in the first direction, the reinforcement film overlaps with at least a portion of a border between a region overlapping with the space portion and a region not overlapping with the space portion.