By grounding a metal first housing, radiation noise generated from the coupling circuit is shielded. Further, by enclosing the first housing in a metal second housing in a manner such that the first housing and the second housing do not come into contact with each other, and grounding the second housing by connecting the second housing to an engine block, radiation noise generated by the capacitive component between the coupling circuit and the first housing is shielded by the second housing. As a result, the influence of this noise on peripheral devices of the high frequency discharge ignition device can be suppressed.