A flat panel piezoelectric loudspeaker includes a piezoelectric element, a first electrode and a second electrode. The piezoelectric element includes a first surface and a second surface opposite to the first surface. The first electrode is electrically connected to the piezoelectric element and disposed on the first surface. The second electrode is electrically connected to the piezoelectric element and disposed on the second surface. At least one of the first electrode and the second electrode includes a carbon nanotube structure. The carbon nanotube structure includes a plurality of carbon nanotubes approximately aligned along a same direction.