An oscillation device includes a reference oscillation unit for generating an oscillating signal of a specific frequency; a voltage-controlled oscillation unit for generating a output oscillation signal whose frequency is dependent on a control voltage; a phase comparing unit for detecting a phase difference based on the oscillating signal and the output oscillation signal; a digital value storage unit for storing therein a phase difference signal corresponding to the phase difference as a digital value; a sample holding unit for intermittently renewing and maintaining a hold signal in accordance with the digital value; and a control unit. The control unit controls the reference oscillation unit, the phase comparing unit and the digital value storage unit to be started or stopped, and also switches the control voltage to the phase difference signal or to the hold signal.