An actuator device includes a plurality of piezoelectric elements formed on a surface of a substrate. Each piezoelectric element is configured of a piezoelectric layer, an upper electrode, and a lower electrode that is formed across the plurality of piezoelectric elements. The actuator device also includes a thin film portion provided to a region in the lower electrode between each adjacent two of the piezoelectric elements. The thin film portion has a thickness smaller than that of a region in the lower electrode provided to each piezoelectric element. The actuator device also includes a concave portion provided to the boundary portion between each thin film portion and the piezoelectric element adjacent thereto. In the actuator device, the inner surface and an edge of the opening, which is opposite to the adjacent piezoelectric element, of the concave portion are formed into curved surfaces.