To provide a crystal oscillator which has sufficiently high accuracy and operates at a low voltage level by outputting the varicap control voltage decided by the temperature of an oscillation part to a varicap as a varicap control voltage signal.

This temperature compensation type crystal oscillator is provided with a stabilized power circuit 1 which supplies the constant voltage, an oscillation circuit 2 which has a crystal vibrator 21 and a varicap 22, a temperature detection circuit 3 and a temperature characteristic compensation part 4. The circuit 2 oscillates the prescribed frequency when an oscillation part is set at a prescribed temperature. The circuit 3 includes a temperature detection element at a place near the circuit 2 and detects the voltage corresponding to the temperature of the oscillation part based on the temperature voltage characteristic of the temperature detection element. The circuit 3 also outputs a detection voltage signal VTemp. The part 4 generates the varicap voltage which varies by the signal VTemp and is applied to the varicap 22 and outputs this voltage as a varicap control voltage signal VVR.