An integrated ignition apparatus has a coil section and a plug section. The coil
section has a spring as a connection member internally. The spring electrically
connects other inside terminal members of the plug section. When the coil section
and the plug section are integrated, the spring is pressed, and resiliently deforms
in the axial direction. Spring-back force of the spring maintains electrical connection
steadily, and prevents disconnection of the spring and the terminal members due
to vibration. This structure prevents failure in electric conduction between the
coil section and the plug section.