In a directional loudspeaker, an audible sound signal that is modulated with a carrier wave in the ultrasonic wave band is input to a piezoelectric element, and thereby a diaphragm having the piezoelectric element is vibrated and a sound wave is generated. In such a directional loudspeaker, the diaphragm is fixed to a fixed part via a plurality of beams disposed along the outer circumference of the diaphragm.