A power generation device 1 converts vibrational energy into electric power using a vibrational power generation element 2 in which an electret 5 is provided on one substrate 4 of substrates 3, 4 configured to be relatively movable while maintaining a mutually facing state, and supplies the electric power. A vibrational power generation element 10 has the same configuration as the vibrational power generation element 2 and converts vibrational energy into electric power. The vibrational power generation element 10 is connected to a light-emitting diode 15 via a bridge-type full wave rectifiercircuit constituted by diodes D11-D14, a smoothing circuit constituted by a capacitor C11, and a light-emitting diode drive circuit 16. A power generation state of the power generation device using the vibrational power generation element 2 and the like is displayed by blinking of the light-emitting diode 15.