PURPOSE: To prevent mixture of the noise from an output terminal to obtain a stable oscillation output by providing a cylindrical earth terminal around the output terminal.

CONSTITUTION: A cylindrical earth terminal 8 is provided around an output terminal 2 and an optional gap apart from the output terminal 2. By the presence of this earth terminal 8, influences of variance of the voltage and the current applied to a conductor 7 forming a circuit pattern are not transmitted to the output terminal 2. Therefore, mixture of the noise from the output terminal 2 is prevented. That is, electrostatical and electromagnetic coupling between the output terminal 2 and the conductor 7 is not caused, and influences from an external wiring or the like are avoided similarly. Consequently, a stable oscillation output is obtained.