<p>There is provided an oscillator using a high-frequency crystal resonator which can satisfy the drive level needed for the crystal resonator and expand a variable frequency range. An oscillator having an oscillation circuit CC for oscillating the resonator SS is provided with a limiter circuit LM1 as a load of the resonator SS which is inductive and is a load circuit for limiting an oscillation amplitude. According to this configuration, the action of the limiter circuit LM1 allows satisfaction of the drive level needed for the crystal resonator and expansion of the variable frequency range.</p>