To reduce sizes and costs by making the inclination direction of a capacitance temperature characteristics of a capacitor for temperature compensation the same with the inclination direction of a frequency temperature characteristics of an oscillator.

This temperature compensated oscillator consists of an oscillator circuit 2 which includes a quarts oscillator 1a having a specified frequency temperature characteristics and an amplifier and a capacitor 3a for temperature compensation as a temperature compensation circuit which has a specified capacitance temperature characteristics. The circuit 2 including the amplifier is a Colpitts type circuit which consists of a transistor Q1, resistances R1 to R4 and capacitors C1 to C4. That is, the capacitor 3a has a straight line or a linear capacitance temperature characteristics in a prescribed temperature range and the inclination direction of the capacitance temperature characteristics of the capacitor 3a in the prescribed temperature range is the same as the inclination direction of a frequency temperature characteristics of the oscillator 1a. Thus, it is possible to accomplish the temperature compensation of an oscillator with a simple configuration.