To provide a surface acoustic wave(SAW) oscillator or the like capable of compensating a temperature in a simple configuration and surely compensating the temperature even when a SAW resonator has variation in temperature characteristics.

The output signal of a temperature sensor 4 is amplified by an amplifier 11 and outputted to a wind comparator 13. A lower/upper limit voltage corresponding to a medium temperature area including a room temperature is set to the wind comparator 13 by a medium temperature area setting circuit 12 and it is discriminated whether or not a voltage corresponding to the detected temperature exceeds the range of a correspondent voltage set by the medium temperature area setting circuit 12. When the voltage exceeds that range, the contact of a switch 14 is opened and the capacitance of a capacitor serially connected to a SAW resonator 1 is decreased so that the oscillation frequency of a SAW oscillator 2 is increased. Therefore, concerning the SAW resonator 1, the temperature is compensated only in the low and high temperature areas which require temperature compensation.