OSCILLATOR

To provide an oscillator configured to output a frequency signal accurately reflecting a result of a temperature adjustment by a heater circuit. An oscillator outputs a frequency signal with a frequency preliminarily set. A crystal resonator connected to an oscillator circuit is housed inside a crystal resonator cover. Soldering this crystal resonator cover onto the base plate inside the container disposes the crystal resonator on the base plate inside the container. A heater circuit performs a temperature adjustment inside the container based on a temperature detected by a temperature detector. At this time, the crystal resonator cover that houses the crystal resonator is constituted of a phosphorus deoxidized copper.