The piezoelectric element comprises a piezoelectric body extending in a lateral direction and a first and second electrodes that are provided on the piezoelectric body. The piezoelectric body has an active portion sandwiched between the first and second electrodes in a thickness direction that is vertical to the lateral direction, and an inactive portion connected to the active portion in the lateral direction. The first electrode has an active electrode portion disposed on the active portion. The active electrode portion includes an interface region that is adjacent to the interface of the active portion and the inactive portion in the lateral direction, and an inner region that is separated from the interface of the active portion and the inactive portion in the lateral direction. The cross sectional surface area per unit length of the interface region in the cross section of the active electrode portion is greater than the cross sectional area per unit length of the inner region.