A piezoelectric actuating apparatus includes a frame having an opening, a rotatable element, first and second actuating elements, a sensing element, transmission elements, a sensing electrode, and a driving electrode. The rotatable element is in the opening, connected to the frame via a rotating shaft structure, and reciprocatingly swings relative to the frame around an axis of the rotating shaft structure as a center. The first actuating element is connected to the rotatable element. The transmission elements are between the first and second actuating elements, and between the first actuating element and the sensing element. The second actuating element and the sensing element are coupled to the rotatable element via the transmission elements. The sensing electrode is on a part of the transmission elements and the sensing element. The driving electrode is on another part of the transmission elements and the first and second actuating elements.