A crystal oscillator is provided to secure a space for housing the IC and electronic components, even if the vibrator is small in size. In this crystal oscillator, there is not a hindrance to the wire connections between the IC and the electronic components, and the limitation on the vibrator and oscillator design is reduced. Also, the influence of the heat from the IC and the electronic components is made smaller. Thus, desired characteristics can be readily achieved with this crystal oscillator. In this crystal oscillator, the IC and the electronic components are housed in a concave portion formed in the ceramic package. A pedestal formed with a crystal plate made of the same material as the vibrator is provided to cover almost the entire opening of the concave portion, and the vibrator is placed on the pedestal.