A ladder-type electric filter device having rubber plates each provided on one or both sides of each of the piezoelectric resonators so as to be brought into resilient contact with the surface of the associated piezoelectric resonator. The rubber plates are shaped so as to not be brought into contact with the respective corner edges of the respective piezoelectric resonators which generate extensive contour vibrations. Thus, the contour vibrations are not suppressed, the insertion loss can be reduced, and a mechanical quality factor Q can be substantially decreased, thereby improving group delay frequency characteristics.