PURPOSE: To provide a vehicle panel vibration reducing device capable of suppressing displacement generated to piezoelectric material and applying large force to the panel of a vehicle.

CONSTITUTION: This vibration reducing device for reducing the vibration of the panel 30 of a vehicle by applying negative-phase vibration to this vibration is provided with a diaphragm 20, and a base seat 22. The diaphragm 20 is formed of plate like piezoelectric material, and this piezoelectric material generates the expanding/contracting force in the direction along the face when voltage is applied from a driving circuit 28. The base seat 22 is rigidly fixed to the panel 30 while fixing the outer peripheral part of the diaphragm 20 rigidly.