A piezoelectric resonator assembly comprises a single integral plate which is cut to form a peripheral region for supporting a resonator, a central resonating region for resonating in the longitudinal mode, surface-shear mode, or bending mode, and at least two oppositely positioned arms for fastening the peripheral region to the central region at opposite points on the central resonating region. The arms are positioned at nodal zones of the central resonating region. There is a single gap between the peripheral region and the central resonating region at each position about the central resonating region except at the positions of the arms. The entire upper and lower surfaces of the plate are continuous and have metal plates formed thereon for forming the excitation electrodes of the central resonating region. The metallized plates are attached to leads at the peripheral region. Upper and lower cover elements are also attached to the metallized plates at the peripheral region for covering the central resonating region.