PROBLEM TO BE SOLVED: To provide a temperature control circuit for a crystal oscillator with a thermostat which is unlikely to be affected by an ambient temperature change when activated and capable of performing temperature control over a wide range when stabilized.SOLUTION: A temperature control circuit for a crystal oscillator with a thermostat comprises: a PNP current limiting transistor 16 in which a differential between a voltage corresponding to a temperature detected by a thermistor 1 and a standard voltage is amplified by operational amplifiers 6 and 13, output from the operational amplifier 13 is inputted to a base of a PNP power transistor 9 as a control voltage, a heater resistor (seventh resistor) 10 is heated and a current to be inputted to an emitter of the power transistor 9 is limited; and a fourteenth resistor 19, a resistance value of which is changed by the temperature of an emitter of the current limiting transistor 16.
