Piezoelectric element detection method, oscillation device, and vibrating gyroscope

The measurement of the characteristic of the piezoelectric element of the oscillation device, particularly, the equivalent serial resistance value can be carried out without using a measurement device connected to the outside. An oscillation device causes oscillation by driving a piezoelectric element by means of an oscillation circuit, the equivalent serial resistance value of the piezoelectric element is determined on the basis of the voltage-current relationship between the output signal of the oscillation circuit of the oscillation device and the drive signal used when the oscillation circuit drives the piezoelectric element. The oscillation device has a piezoelectric element, an oscillation circuit that drives the oscillation of the piezoelectric element through feedback of the drive signal to the drive terminal of the piezoelectric element, and a drive signal switch circuit that controls the external output of the drive signal of the oscillation circuit.